I agree!
I started shooting weddings a couple of years ago after being in the photog biz for 8 years prior to that! It's a whole lot of work. Let me tell you. You need great equipment, loads of patience, tons of time for post processing and more.
Maybe you could do a little research on some photogs in her area and make a couple of suggestions? Tell her that you want her to have the very best photos and want to help but might not be the best person to handle the whole shebang.
I like the idea of offering to take the candids while someone else does the set up shots.
And I also think she should calm down a bit