Kelly Osbourne is reflecting on her journey as a mom so far.

The reality star showered her and boyfriend Sid Wilson's son Sidney with a whole lot of love on his first birthday, posting a heartfelt note about life with their baby boy.  

"This past year has been the most magical year of my life for one reason," Kelly captioned her Nov. 6 Instagram post. "That reason is you baby Sidney. To watch you grow, learn and become a little man is the greatest joy I have ever felt."

The 39-year-old then took a moment to explain how becoming a mom to Sidney changed her outlook.

"The most magical bond I have ever experienced is the bond I feel with you," Kelly gushed. "Before you, love was just a word that I thought I understood. NOW I truly understand what love is. I am forever indebted to you for teaching me the beauty, meaning and truth of love. What more can I say other than I love you. Happy birthday, sweet price. We made it on our first trip around the sun together."

As for how The Osbournes podcast host celebrated Sidney's special day? Well, she threw her little one a spooktacular birthday bash. 

Kelly gave a glimpse from his party on Instagram, sharing a video that showed a "boo" themed bar that housed a cauldron bubbling over with smoke, skulls and purple and black decor. A black-and-white play center was set up for the kids while green, purple and black balloons decorated the entrance of the house and ghosts hung from the trees.

A sweet moment showed Kelly, Sid and Sidney posing together for a family photo before celebrating with a metallic ghost cake.

Earlier this fall, Kelly got candid about her motherhood experience thus far. 

"I'm a mom now, I love it. It's the best thing that has ever happened to me," she told E! News in Sept., before noting, "It's scary as f--k because you don't want to make a mistake."

But while navigating parenthood, Kelly has taken some keen advice from her parents Ozzy Osbourne and Sharon Osbourne. As for the words of wisdom the longtime couple—who are also parents to son Jack and daughter Aimee—has given?

"It's not about you. Now, your life is about your child," Kelly recalled them sharing. "My mum is trying to get me to not be so attached to the baby right now, because I don't do anything unless it has something to do with my baby, and she's like, 'You have to take some time out for you.'"

However, that advice may be easier said than done for the new mom.

"I try and do it," Kelly confessed, "and the next thing I know, I'm sneaking out the back door to go home to be with my baby."

But Sidney is equally attached at this stage.

"Now my favorite thing is that he is, like, mom-obsessed, just where, if he sees me, he is reaching for me," she explained, "and I love it."

For a look at all of Kelly's candid motherhood comments, keep reading...

"It's scary as f--k because you don't want to make a mistake," Kelly Osbourne told E! News in September about becoming a mom to son Sidney with Slipknot DJ Sid Wilson.

"It's all these little tiny things and these mistakes that you ultimately make because you can't learn unless you make a mistake," she explained. "It's just unfortunate that you have to do it with a baby."

Kelly was diagnosed with gestational diabetes "well into my third trimester," she told People in September 2022, "so it wasn't like I developed it as some people get it from the get-go when they're pregnant. I got it in my third trimester and basically, I thought it was something that I had done wrong."

Her only pregnancy craving had been sugar, especially sweet drinks, Kelly explained, and even though she tried to temper it by drinking fresh-pressed juice, "it still had a lot more sugar than I needed."

Once she made purposeful changes in her diet, she continued, she suffered from a sugar-withdrawal headache for awhile but ultimately lost 10 pounds, stopped having to wear compression socks and her skin cleared up.

"I wish I had this kind of incentive prior because I've never been able to stick to anything a hundred percent the way that I have been doing this because I'm not doing it for myself," Kelly said. "I'm doing it for my baby. But I have learned—I can't even begin to tell you the changes that it's made."

What mom doesn't look at her kid sometimes and marvel, Hey, look what I made?!

"No, I cannot believe I have a baby," Kelly said on TODAY in May, talking to Hoda Kotb and Jenna Bush Hager ahead of her first Mother's Day.

"I have a beautiful little baby boy," she continued, "and he is my reason for living, my reason for getting up in the morning, my whole life revolves around him. And now I understand what the word 'purpose' really means."

"I have a new found respect for working mothers," Kelly wrote on Instagram Feb. 19. "I took my first job since having a baby. Having to leave him this morning was one of the hardest things I have ever done. This day can't go by quick enough for me. I can't want to have him back in my arms."

She solved that problem the next day: "I could not leave him again so it's bring your #BringYourBabyToWorkDay," she posted to Instagram Story.

Just because she can wrangle some alone time, actually wanting it is another story.

"My mum is trying to get me to not be so attached to the baby right now, because I don't do anything unless it has something to do with my baby," Kelly told E!, "and she's like, 'You have to take some time out for you.' But I try and do it, and the next thing I know, I'm sneaking out the back door to go home to be with my baby."

While some celebs host a real bumpfest on social media, flashing bare bellies right up to their due dates, Kelly was admittedly self-conscious about sharing her journey in real time with millions of people (after announcing that she was expecting with the aid of a few sonogram snaps).

"There are no pictures of me pregnant," she replied in August to an Instagram commenter who asked if she'd used a surrogate to deliver Sidney, "because I hid for 9 months because I did not want to get fat shamed."

She also couldn't help comparing herself to the ladies who leaned into their pregnancy silhouettes in public.

"You can wear so many things that weren't considered appropriate before and then Rihanna changed it for everyone," Kelly said on Dax Holt and Adam Glyn's Hollywood Raw podcast. "Also, it made me sad because I didn't get to show off my pregnancy belly because I literally was a f--king moose and it was embarrassing."

Kelly admittedly wanted to get back into fighting shape as soon as possible after Sidney was born.

"I'm going to be honest," she told E! in September, "I felt the pressure of, after having the baby, to lose the baby weight. It became my mission. I was obsessed with it because I didn't even want to get brought into the conversation, I just wanted to be left alone."

Getting it done was "miserable," albeit worth it for her in the end. "I was hungry all the time," she shared, "but I'm really happy with the results."

However, at one point she decided she was overdoing it.

"I was like, 'Well, I lost all the baby weight. Let's see how far I can go with it,'" she told Scheana Shay on the Sept. 8 episode of her Scheananigans podcast, "and then went a little too far."

Having been candid in the past about setbacks in her recovery, Kelly marked a year of sobriety on May 27, 2022, a few weeks after announcing she was pregnant.

"What a difference a year can make!" she wrote on Instagram. "If you would have told me 365 days ago that I would be sober, happy, and about to be a mumma I would have laughed in your face. Life is truly amazing when you do the work. Thank you to everyone that has supported me on this journey. I love you all so much!!!!!!!""