Medium rats are fine.
Depending on where you are ordering from, you can ask for smaller mediums, or if luck of the draw, usually average 110-130g, which is fine for her at 1,000g.
If shes still growing, I would offer every week still, if she eats every meal. If she starts skipping meals, separate from her winter fast (if she fasts), then go to every two weeks.
Probably around 1,200-1,300g my female BP started skipping meals regularly when feeding weekly. This during the spring and summer and not during her annual 5 month fast.
I’ve been feeding every two weeks since and she’s 6 now, about 1,800g, and I am wasting a lot fewer rats.
Instead of eating 3/5 meals, or less. She eats 4/5 or even 5/5 depending on the period.
She skipped her last meal and it was her first miss in 3 months. She also may be starting her fast now.