The 33-year-old was pictured heading into the hospital Kelly gave birth at earlier today and has spent the day with her, and little Titan Jewell.
Next to the snap, which sadly isn't little Titan (we actually think she may have taken it from Google), she wrote:
“There's no better feeling than holding my beautiful nephew. I thank god for the honor of witnessing my sisters journey into motherhood.
“I've always dreamt of our little ones growing up together. I'm so thankful for our bond. Baby Ty, I love you so much. Congrats to my Spoons.”
Kelly gave birth to Titan, with her husband, Tim Witherspoon, yesterday.
Her other Destiny’s Child bandmate, Michelle Williams, said yesterday Kelly was going well before adding:
“Kelly's going to be an amazing mom. She's always been great with children. She loves babysitting, she loves buying stuff for kids.
“She has such a big heart. She's a giver and a nurturing person and, really, that's what motherhood is all about.”
Happy birthday Beyonce! Check out her good, bad and Bey-ootiful looks
1 of 20Golden in 2004
Remember when Bey's mum, Tina Knowles, used to design frocks and dress the star? Oh yeah.
2 of 20Sateen in 2007
Back in the day Beyonce used to love a bit of shine. This brown two-piece was a treat. Or maybe more of a trick...
3 of 20Loving green in 2007
Yet more satin, this time a fishtail green number that would make Miss Piggy go weak at the knees. If she had any.
4 of 20Mellow yellow in 2008
When you have a matchy scarf for your bridesmaid-inspo gown, it's time to re-think your style.
5 of 20Awards Bey in 2009
Taking the Oscars gold theme a tad far in a frock that made from Laurence Llewelyn Bowen's bedroom curtains...NAAAHT GOOD.
6 of 20Skinny Minnie in 2009
Sleeker but rocking shoulder pads that'd make Hilary Devey jell.
7 of 20Spotted in 2009
We loved Bey's cute spotty playsuit but her hair looked like it had seen better days...
8 of 20Red alert in 2009
That's more like it! Beyonce wowed in a red hot mini with MAJ plunge at the MTV VMAs a few years ago.
9 of 20Feathered friend in 2011
Looking elegant in a white halterneck with feathers at her perfume launch in NYC.
10 of 20Legging it in 2011
Proving she can nail off-duty, too
11 of 20Bumpy in 2011
Best baby bump reveal EVAH in siren red at the MTV VMAs.
12 of 20Yummy mummy in 2012
Didn't take this one long to bounce back to HAWT post-preggo, eh?
13 of 20Dramz in 2012
Bringing the dramz in Schiaparelli to the MET Gala in 2012.
14 of 20Braidy bunch in 2014
Taking style inspo from her little sister Solange with mega long braids.
15 of 20Maverick in 2012
SO not the norm Beyonce but we loved this boho vibe.
16 of 20Jumper in 2013
Who needs a massive frothy frock for an awards bash? Not Bey! Bow Down queen looked incred in her mono jumpsuit with red lips at the Grammys last year.
17 of 20Sheer in 2014
Dramatic style for this year's MET Gala, wearing a sheer beaded gown with vampy lips and a glam head piece.
18 of 20Stage Bey in 2014
Beyonce on stage in thigh-high boots and a bodysuit. No words. Just WOW.
19 of 20Plunging in 2014
The singer's first look for this year's VMAs was a risque LBD with sheer paneling all over her butt. She totes pulled it off, too. Not literally, obvi.
20 of 20Second wind in 2014
The mum slipped out of her LBD for awards pics, changing into a ruby bodycon number with lace side panels. Racy.