Needing to vent!

Brittany • First time mommy❤️ I work in a body shop, my boyfriend has a 7 year old who I love as if he was my own.
What do I need to do? Is this considered a threat? Harrasment since I'm pregnant? I'm livid right now and she has always had control of my fiancées life and we always have to "do what she says" she falsely accused my fiancée of hitting her and made it to where he couldn't see his kid without supervision, he has been trying to get a divorce from her for idk how long now, she refuses to get one unless he gives her full custody of their child, pays ALL HER DEBTS, ect and now this? The message is sent from a pinger number where the number can't be traced or proven that it's her but we are going to the clerk of courts Monday about it and the sheriffs office tomorrow for these screen shots to be put on file for if something DOES happen. This was sent to my fiancée. We haven't told the family we are having a baby until Christmas and now what do you all think will happen when she finds out? But still yet she lives with her boyfriend etc.