Creditor got ahold of x-wife and her sister!?

I got a message from my x last night (been divorced for 7 years) and
said that XXXXXXXX called her AND her sister and told them I was
a "skip". My X and especially her sister have nothing to do with my
debts. Can a creditor legally tell someone that about another person?!

How in the world did they find a way to contact her who lives in
another state and her sister who I don't even know where she lives.

She's also worried that it's going to affect her credit which to me
would be impossible since all my debt accured years after our divorce.