Your preceptor has two patients, and then you so she will be picky. Especially about turning...

Anyways it's only a few more weeks just hang in there, they are her patients that's why she wants things done her way. When you're on ur own you will do things ur own way. If she belittles you change preceptors, if she's hard on you and keeps asking you questions then stick it out. It's not that easy to train in ICU, it's not like nursing school...But if you can't take it anymore...I'd speak to your preceptor first and not your manager.