"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 ...

Here are some ideas for your social media post: "Happy Birthday to my forever partner in crime! Love you, sis." "To the one who’s always by my side, happy birthday! #SisterGoals" "Wishing my ...