Entertainment TV Reese Witherspoon Posts Adorable Birthday Message to 'Big Sis' Jennifer Aniston: 'What a Gift' "You always give the best advice and endless LOVE and support," Reese Witherspoon wrote in honor of Jennifer Aniston's 54th birthday alongside photos of the Morning Show costars By Alexis Jones Alexis Jones Digital News Writer, PEOPLE People Editorial Guidelines Published on February 11, 2023 04:51 PM Share Tweet Pin Email Photo: Kevin Mazur/VF17/WireImage Reese Witherspoon is wishing her "big sis" Jennifer Aniston a happy birthday! The Your Place or Mine star shared a sweet birthday message to her Morning Show costar on her 54th birthday Saturday. "Happy Birthday @jenniferaniston! What a gift to get to work with my big sis every day on @themorningshow," Witherspoon, 46, wrote as a reference to when she guest starred on Friends as Rachel's (Aniston) sister, Jill Greene. Reese Witherspoon Proves She Still Remembers Her Lines from Friends 23 Years Later "You always give the best advice and endless LOVE and support. I 💖 you, Jen! Everyone wish her a Happy Birthday!! 🎂💫" she concluded the caption. Along with the birthday tribute, Witherspoon shared several photos of her and Aniston from their time on The Morning Show, as well as one of them in 2014 at the Stand Up to Cancer telecast. Kevin Mazur/American Broadcasting Companies Inc via WireImage Reese Witherspoon Shares Snap with Jennifer Aniston During 'Last Days' Filming The Morning Show Season 3 Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. On Instagram Wednesday, the Legally Blonde star posted a series of behind-the-scenes photos from The Morning Show, including one snugly shot of her and Aniston. "Last days of shooting @themorningshow! Season 3 is on the WAY!" Witherspoon, 46, captioned the carousel. The two actresses play frenemy news anchors Alex Levy (Aniston) and Bradley Jackson (Witherspoon) on the Apple TV+ drama. No premiere date has been announced for season 3 of The Morning Show.