My 15 yr old daughter told me that a friend’s mom is spreading rumors about her sharing inappropriate pictures of her to other parents. I trust my daughter. What can I do about the situation so it doesn’t affect her negatively?
I applaud you for trusting your daughter. This situation is absolutely worth investigating. It already seems to be affecting her negatively so it feels like it's time to help. I know it's a delicate balance in parenting figuring out when to step in and when to let our children learn difficult life lessons, but when it comes to safety and well-being we always need to step in. In this particular case, your daughter is asking for help. No matter what sort of aftermath comes from confronting this situation directly, it is better than avoiding the confrontation and allowing the behavior to continue.
I understand I don't have all the details but it sounds like harassment of a minor. Confronting the adult responsible (the friend's mom) directly is always an option. You are your daughter's advocate and she needs an adult to step in and stop this behavior. If the situation warrants getting police involved, then I wouldn't hesitate to do so. Depending on the context of the situation, perhaps a school advocate can help sort things out. For example, if this is happening at your daughter's volleyball games then perhaps seeking support your daughter's school counselor or someone on her Alpha Team would be a good first step.
Gather some ADULT support - whether it is a parenting partner, someone from the school, a friend, etc. Gather all the information you can to determine the best course of action from there. And then address the problem at the source with the support you built around you. It's not simple and it's not easy but it sounds like it would be the right thing to do to address it head-on. That is what makes parenting so difficult! Best wishes...