How would you handle this situation.

Divorced ex wife has been talking to the family friend of my 3 niece's in hopes to gather information. We are still going through custody battles so she is looking for anything. She has bought this girl gifts and gossips with her at her place of work because she works at a dentist office we all went to for years. Ex is 8 years older than her and during our marriage did not have any relationship with this girl nor any great relationship with my niece's.

My oldest niece just lost her fiancee last Christmas and she started using drugs again and self admitted into a rehab a few weeks ago. I actually have not seen her in almost two years.

My ex reached out to my youngest niece to wish her a happy birthday which she has never done through Facebook or any one else in my family but used that opportunity to tell her how sorry she was to hear about her sister. This was not in any way public information nor did anyone inform my ex of her situation.

She is using this opportunity to gather more information in hopes my niece responds. She actually wants to try to link her instability and say I have people in my family that suffer from abuse. I don't live near them, do not have my kids around her or anything.

Back story, my ex actually asked my niece with the problem to get her pills years ago and her family is very disappointed with my ex to ask someone with a problem to help get them something which at that point was a minor.

The niece she reached out to wants to respond and not blast her but ask her to stop gossiping with their family friend and stop stalking social media and to leave her and her family alone and out of it and is upset how she is using a friend to get personal information.

What would you do? Everyone that knows my ex knows what she is doing and honestly it is just to start shit. Below is what she asked me if she could send back as she and her family are sick of it.

Thanks for wishing me a happy birthday but after this please do not reach out to me. It is weird that you have never sent me a text or facebook message to me, my other sisters, my mom or dad or anyone else and you randomly reach out to me since you heard something about my sister and you reach out. We never had a close relationship and what I do remember is you always reminding my sister and me how stupid we were because we lived in a specific area, sorry it was the best my parents could afford, how we both would never make it into college, my sister would never become a nurse, she has, how trashy we dressed, and everything else that we did wrong and not to your level. My entire family has never once contacted you and after you kept following me and posting on my Twitter, Instagram, Snap Chat and Facebook I blocked you on everything as I do not want to be stalked by you neither does anyone else and I have never reached out to you or anyone in your family to address something I heard. I have no idea what you are so sorry about of what you heard about my sister. I never told you or did anyone else in my family about anything. So please stop talking to our family friend and next door neighbor, buying her gifts and whatever else, you never where close with her and it is strange that you gossip with her at her work or anyone else about us. You have done enough to hurt my sister and no one has done anything like this to you. Please block me as I have done and spend your time on worrying about you and your kids, not other people’s drama as you have no clue what happened or didn’t happen.