You're asking for trouble assuming in a group mostly of women that she's not strong enough to do it LOL! I would assume that the majority of us who start this cannot do full push-ups let alone a pull-up! If you were to offer me a million dollars to do a pull-up I couldn't. But I might pull off dead lifting over a hundred pounds
She's going to do great! Women are strong. She'll do great! I'm only getting towards the end of Stage 1 and I went from not being able to do a push-up to doing them on the floor. She'll do just fine. Have faith that she is a strong strong woman.