I would def get her in to have a look at these!!
I'll bet that most of us have picked/bitten/peeled our gel polish off ,with minimal damage to our nails, so how she managed to do such damage to hers is interesting, to say the least, especially as there's a wedding coming up..
I, too, reckon she's after a free service, however..it does sound as if she MAY have had extensions in the meantime after seeing you,as she had her service with you a month ago, and possibly didn't like them and has pulled them off herself, which may have caused the damage she is suggesting was caused by gel polish??
Surely any remover that has acetone in it will remove Gelish? I have tried a few types in my time..all seem ok, unless of course, client got non-acetone remover, which of course wouldn't work...
Def need to ask some probing questions on this one, use 'open' questions that start with who, what, why, where, when & how, that way she has to tell you what happened, not just yes or no answers..
Please let us know how this turns out..