Four mice at a time, once every week or two, is not so bad of a meal. BTW, it's better to give a bunch of mice once a week than one mouse every day. Pythons' systems are adapted for processing occasional large meals, not frequent small ones.
But if nothing else, it's definitely more convenient to give one rat than a bunch of mice. You could also try giving her pre-killed or thawed food, which is also more convenient and can't bite back.
You'll read lots of different recommendations for how much and how often to feed, but I suspect that for an adult that isn't breeding and isn't growing anymore, less is more. She doesn't need a medium rat every week.