You have a TA!???
I’ve had some peer tutors in a few classes before, and I feel the teacher is in charge of the class. You are the teacher, it’s your class, you need to take charge. The TA/tutor is there to support the students in their work or to do some administrative assistance, like photocopying, some marking of tests, etc.
If the specific job description of TA where you’re from is different, then have a discussion with them about how the two of you can collaborate more effectively.
Teaching In Real Life 