Yeah, I'm not sure about the 10% rule (at least not for adults). I am considering purchasing a 3000g female and I do not see me feeding her more than one 90-100g rat every week.

As far as switching her to rats, I may just give it a try later or like WingedWolf said, maybe after the season. She would not take the mice I offered her last week so I just left two of them on the cool side of her tub. I came back 3-4 hours later around 2am and they were gone.....eaten. I may just leave a F/T weaned rat in her tub and see if she takes it next time. It seems that she is just a shy eater and likes mice for whatever reason.