My Boyfriends EX's Girlfriend.....

Im currently in the process of getting custody of my boyfriends 2 year old daughter, he is incarcerated but I am taking on responsibility of her because her mom is using & I want the baby safe before ending up in the system. BUT here is one thing that bothers me, his baby's mom will text me that she misses my boyfriend, she has to move on for the sake that he moved on, she wants to go visit him and so on.... I feel like she does this to agervate me and there are times I don't even response to the nonsense but now the text are getting out of hand. What should I do? 😁