Gossip is never harmless; it distorts the truth about people and almost always is intended to tear them down. The Bible rightly says that "A perverse man stirs up dissension, and a gossip separates close friends" (Proverbs 16:28). It also says, "He whose tongue is deceitful falls into trouble" (Proverbs 17:20).
How should you deal with this? First of all, be sure that you don't fall into the same trap as these women. It's easy when someone is gossiping to respond with another "juicy tidbit" about someone–without even realizing what you are doing. Don't let this happen to you. The Bible says, "The lips of the righteous know what is fitting" (Proverbs 10:32).
Then ask God to give you an opportunity to share your concern with them privately. Gently tell them that you care about them and consider them friends, but you are concerned that their words might be hurting someone, and you hope they'll be more careful in the future. If necessary, however, simply walk away from them when they start gossiping.
Don't worry about what they might be saying about you; others know the kind of person you are, and they will only damage their own credibility. Above all, pray for them, and ask God to help you be a witness to them of Christ's love and peace.