I would say her size is normal. If you aren't feeding her rats yet, I would consider making the switch as soon as possible. It tends to get a lot harder to do so later. When snakes are on the move like that it normally means they are looking for food. I have 4 hatchlings and when they are fed well they don't normally come out during the days for about 3-4 days(they tend to be active at night though). Then I tend to feed again on the 5th day.