That sounds exactly like my teacher (even though mine is piano) lol. If you asked her what you were doing wrong and she didn't tell you or she didn't explain well, and if this keeps happening then maybe you might want to consider switching teachers. If you haven't asked how to do it correctly or how to use your diaphragm etc., then you should def. ask her and see what she says. But I dont think that 2 lessons are enough to decide whether you should switch teachers or not, ask a few more times, if it doesn't work out after a month of so, then consider switching. If it starts to get better then just stick with her. A lot of teachers do the "yes, no" thing because they want you to notice what you are doing right and wrong, but clearly since it seems like you are not getting what you are doing right or wrong (sounds exactly like me) you should ask her.
hope i helped!
good luck
hope i helped!
good luck