I don't want to over feed my girl but I ddont want to under feefeedher.

When we got her a month or two ago, it took her 15 minutes to eat a medium rat and now she can eat one in 5! The breeder said most ball breeders don't feed larger than medium rats because you just end up paying money for poop. (Meaning it's more food than needed.) She's 6.5" around (I measured her belly around with a soft measuring tape,) and that seems to be the size of a medium rat. She never refuses food either! She's a great nommer!!

I also feed her every Sunday, but I'm reading sites where people say 10-14 days.

So, 1. Is a one medium rat per feed USUALLY a good size for the life of a ball?
2. Do I feed every 7 days? 10? 14?