Look, dude, it Sounds like she's made it clear she'd like you and your instructor buds to leave her alone. She doesn't want it and it isn't important to her or her happiness, and as a woman in her 50's she's earned the right to make that call. Skiing isn't a passion for everyone.
Perhaps the situation is very different that the way it reads, but you sound a bit like an Amway salesman friend I once had...he could believe I didn't want his life altering products either.
Granted, PMTS is way, way, better than Amway.
and it would help her ski better, of course.
There are tons of folks out there who really do care about skiing better, however,I am sure you won't have to look to far to find a more willing project.