I suppose OP was more thinking about whether punting can be a long-term career plan... I would agree that if a girl has been doing it ever since her early twenties, it's certainly possible she will get burnt out by late 20s early 30s. Most of the girls I've spoken to don't intend to do this forever. But let's not forget some girls start punting a lot later, often once they are married and the husband is out working, they will work part-time to supplement the family income.
For me personally, I wouldn't see anyone over 40, but I'm still young so preferences may change once I have reached that milestone myself.