What does this mean? What is an Ed Hardy bikini and why would it be odd for a mature woman to wear?!
Google is your friend for the first part of this question.
I can't imagine wearing one for work (unless there is a hot tub on the premises?) so I wouldn't personally say there's an age limit; wear one if you enjoy silly bikinis!
And for the last part of your question - well, all punters are completely entitled to their opinion and should definitely write what they honestly think in their reviews. However, it's a good idea not to read too many of them if you're an escort. Mostly all you learn is how silly some men are.
I don't think it's uncommon, after you've been working for a while, to have reviews of your own that you don't even understand - I've got a bad review somewhere saying that I'm fat, live in a pigsty and don't do OWO, but I've also got tons more positive feedback saying entirely the opposite. I have no idea who the bad one came from and, if I did indeed meet him, we obviously didn't get along if he was so stinky I couldn't give him OWO. And I know other escorts who've got great reviews but unfortunately the content is also, um, slightly incorrect: "I made her cum 10 times and she begged me not to leave", "I stuck three fingers up her bumhole and she luvved it!!" etc.
So you've probably already seen for yourself how ridiculously inaccurate (and almost pointless; anything beyond "Yes, she is exactly as advertised and was a really nice person" is pretty much the experience of that punter only and may not apply to Joe Stinkerson McMiserybogs) some reviews are - worrying about one guy's feelings towards a certain type of bikini is an enormous waste of your time.
Focus on your clients and the good ones will tell *you* whether or not they like what you're wearing/saying/doing, rather than going home to write a petulant essay about it! And since very few of us are entirely able to avoid all miserable old toads in our careers, if you ever do get mysteriously horrid feedback that doesn't make sense to you, contest it if you can but make sure, more importantly, not to let it get you down; there's no point losing other potential clients and income just because ol' McMiserybogs wanted to hit you where it hurts [your business].
Sorry, that went well away from the original bikini question, didn't it.