Apologizing to non-mahrams-permissible?

Is it permissible for a women , to apologize to non mahrams , if in past they were friends and she hurted them a lot and now she has cut the contacts with them and is focusing on her religion. And she regrets how she has treated them , and wants to apologize to them about it and explain to them , that she doesn't want to have make friend now , can she ? If one number is of his mother and she thinks his mother would most likely tell her mother and don't want to message in that number as she feels shy that his mother will know and then her own mother . So can she approach that person outside if she sees him and apologize to him . Thank you