My heart goes out to you and your daughter. I have not personally experienced with my daughter what you have with yours.
My advice at this point is to recognize that whether we agree with it or not, when our children are bullied by another online we need to defend that position with facts as there are not always witnesses to the offensive behavior. Documentation is important.
I have downloaded an application – no tech expertise needed – called “Jing”. Jing allows you to “screen capture” and save what is on a website, profile page, or your desktop. You should capture the ‘evidence’ to document the offense.
I don’t know what state you live in, but depending on the state some schools are required to get involved when there is harassment/bullying online.
In addition to finding out if you can engage the school, my recommendation is that you use ‘Jing” to capture the screen shot of the incriminating evidence of what has happened to your daughter. Save those screen shots to use to share with the other parent, and when necessary with the school or authorities.
I have found that it is much easier to pursue making a positive change when you have objective facts behind you to support your position. Us moms are mother bears so know that the mother of your daughter’s bully will think you are the one at fault and her child could “do no wrong”. It does not sound like you take a nonchalant position. Know that bullying quickly escalates, and you are your daughter’s most fierce protector and advocate. I commend you for being an involved parent.
I don’t recommend ever contact a child directly about the issue. Either online or in person. You likely would not be having a private conversation with a child (other than your own) when there’s not a computer involved, so don’t have one now with a computer involved. Finally, if at all possible, youth crisis counselors will recommend that after an incident – when there has been a cool off period – the kids get together to meet and agree to move forward with their mistakes behind them. I personally know this can be a challenge to champion doing, but it is an option to consider.
Please let me know if this helps or if I can do more to help you. My heart and prayers are with you.
Mary Kay Hoal