iv had 7 rats in total in my life and now i just got this new baby rat about a month ago (she about 8 weeks or 9 weeks now?) and she eats alot!, and her cagemate eats but not as much as she does and out of all the rats iv had iv never seen one eat so much is this normal?

Rats do eat stacks. If I let them, my boys would spend all day eating. If you are worried about her intake, either reduce the amount of food you are giving them or feed them seperately. Monitor their weight and make sure they don't exceed normal levels. I've successfully coaxed my biggest boys down from over 700 grams to 650-ish in a month or so. Ratty weight watchers! :P