Any advice on how to deal with a bitter ex/ baby momma (hate that term)?

My husband and I been married for 3 years now. He had a child with his ex and well things have never been well since her pregnancy with their child. When I came in the picture she had a problem with me and has cause a lot of problems for my husband like keeping the baby away from him, blocked him off every possible way to contact her like she completely went IMA. She’ll contact me thru social media talk smack and then block me

my thing is I don’t think that’s easy for any woman to deal with another person like that. She claims my husband is a dead beat and isn’t there for their child but that’s not true (and I don’t just vouch for my husband bc his my husband but because he’s been an excellent father to his boys even before the baby and I came along his ex wife could vouch for that and the kids too)

I have a child of my own who has nothing to do with any of the situation but she always bring him in as why my husband can be a father to mines but to their own.

How can you want a parent to be there for a child but keep him away at the same time, everytime my husband would ask for him she’ll say no, she’s to busy, she can’t meet, or just bc “your wife”. I’ve had my words with her plenty of times but I just don’t kno what to do or how to be supportive towards my husband when he’s dealing with a situation like this. Specially now recently she unblocked my husband off snap chat and asked for our address for her lawyer bc my husband hasn’t seen their child in a year and it all due to her keeping him away we have no idea where she has lived, I guess until court papers come in? (We don’t even know what she’s coming for or wanting).

We just recently found out we are having a baby of our own and well I’m afraid of what’s to come I’m trying to stay positive and supportive and over all Asking God to help us keep peace and over all a healthy pregnancy and results!

Any advice will help and well I will like to thank you ladies in advance for you time and advice!!!