I got my BP back in August (age unknown) from petsmart. At the time they were feeding her fuzzies once a week, which I quickly learned was too small. Since then I've been slowly up-ing the size. I currently feed her 1 'large' (as determined by the f/t mice that are sold at petsmart) mouse once a week. She's about 2-2 1/2ft I think but is still somewhat skinny since she's putting on weight still.
I've seen a lot of people suggest rats over mice but I haven't been able to find any rats at any pet stores and I cannot breed my own.

Advice on size and rats vs. mice?
(I've been judging size based on the 'fattest' part of her rule)