“Happy 20th birthday, @applemartin 💕,” Gwyneth, 51, wrote via Instagram. “How can it be that you are 20 today? It feels surreal!” In addition to sharing a throwback photo of her ...

The Goop founder, 51, shared a sweet post on her Instagram in honor of her daughter Apple's 20th ... Favorite Things' "Happy 20th birthday, @applemartin 💕How can it be that you are 20 today?