Ferrets are very picky. Luckily when I adopted mine they took to the new food pretty quickly. However, one of them, Bandit, still hardly eats treats. He was never fed treats at his old house, and he just dosen't care for them. I've seen him eat them once or twice, with the exception of when I toss them in the food bowl, then I think he might just eat them by accident.
But I've never been able to get either one of them to eat wet food! Most of the sources I read reccomended this in case I needed to medicate via food someday, and they just wouldn't have anything to do with it.
I also read that it's good to mix 2 foods together, in the case that one is out of stock at the store when you need it, or the store stops selling it, so at least a picky ferret will have something to eat. I took a dietary chart I had when I was looking for foods and got the Ultimate 8 in 1 ferret diet and I mix it with Nutro Max Kitten food. Seems to do pretty well for mine.
DEFINATLY look into getting her a fuzzy friend. I adopted Bandit about 2 months before I adopted Oscar, and I could definatly tell a difference in Bandit's attitude and energy when I added Oscar- Plus if there's days I can't take them out as much as usual, they have eachother to romp around their cage with.
I have this cage for them:

Minus the tubing. I love it.
And, if you haven't yet, Ferrets For Dummies is the best book I have found yet for ferret info. (And I literally read everything I could get my hands on when I was getting my ferrets!)