I'm not talking about the potty-training phase, but years down the road. For example, if you're in gridlock traffic or a theater, etc., and you have a 6- year-old who "really has to go, " you're likely to accommodate somehow, and fast. But then they get older.
I know that girls (and women for that matter) can (and often do) generally wait much longer, partly because they have to and are used to it. So there has to come a point at which you hold her to the same standard as yourself or an adult friend, etc.
For example, when at an ice cream shop with you, she can always ask the staff "Do you have a restroom?" herself, but is expected to react maturely to either answer, with no special accommodation from you or anyone.