You'd know more than I do about that, but I don't think you use a toothbrush for that sort of thing.
Okay, well, maybe you do :-/
Actually, if you want to gain reliable, useful muscle, you have to gain fat as well. Muscles need energy to do their thing, and fat is the way that energy is stored. That's why strongmen are just so freaking huge, compared to wasp-waisted bodybuilders who actually aren't nearly as strong as they appear to be (hypertrophy, look it up.)
I was merely referencing a source of protein she could obtain with a good workout as a precursor ... a.k.a. sexy time with dongs.