I don't think there is necessarily a "red flag" associated with these jobs, it's not like she is a stripper or prostitute lol, but there are some things to consider.
For all three jobs, there is the element that she will be hit on a lot and readily acquire male attention, especially if she is attractive. This isn't really a red flag but something to consider. I'd especially say this is the case if she was working at some place like Hooters or working at a bar/club where the women dress in skimpy attire, which is very common for a lot of popular nightlife venues.
As for the flight attendant, there's definitely the element where she will be travelling a lot and in all sorts of different cities on a regular basis. She is going to have access to all sorts of varieties of men rather readily, all she needs to do is go on tinder or sit at a bar and she'll be able to find a guy to sleep with for the night. The particular issue I would see with a job like this would honestly be the fact that she is always away for work. IF you are looking for a relationship, this would definitely get in the way potentially.
As for the bartenders. One thing that I will add is that I would find it a bit strange if a woman were to do this if she was closing in on 30 or over it. At the right venue, female bartenders can make a lot of money. However, as a man that doesn't really drink or party I would just assume that we wouldn't have much in common, as she is potentially a "party girl".
