In my working life, I am a trainer...and I'm going to suggest that any good teacher would make you feel free to spread your wings and fly, rather than hold you back. In fact, they would kick you out of the nest if they saw you were afraid to fly. There are a million ways to create a quilt, and in my opinion, the only "rule" we should all remember is "DIFFERENT ISN'T WRONG."
This lady who is mentoring you is so caught up with her own "correct" ideas, she's missing out on some great, innovative techniques, and I suspect she's not enjoying her hobby as much as she could if she'd loosen up her corset and breathe. I'd love to meet her, because I'd tell her that she herself has an awful lot to learn about quilting.
*Off soapbox*
Now, you finish this quilt however you like, and if you make a mistake, guess what? You either fix it, or you move on. But you're not going to let this person paralyze you. You're going to flap those wings and SOAR, little birdie! When you're done, please post pics of your finished quilt for us to admire.