My last email to them I simply said repeated that the costume link I sent them should help, and that since I had no experience in costuming (which is true) I couldn't offer more advice than that. I've since received a plain and short 'thanks for the help' email back...

I would agree with you.I don't thnk I would want to get involved in that situation.A child's life is to valuable to "play" with.This mother may mean well or she may be completely off-side.