Yes i never see her.You're too far ahead, You haven't been introduced to Kendra yet, you can only steal from the hospital once you start doing her quest.
Also what to you mean by you can't complete the quest, with the shady man at the school.
Personally I would recommend starting a new game following the walkthrough, unfortunately the game is at the stage where it advisable to use the walkthrough to play it.
But i have the scene with Emma and Kelly at the pool.
I have the medecin in my inventory, but i can"t give it to the guy
This is the problem i think,i don't use a welkthrough, somy save is probably messy