Husbands ex-wife always butting in on phone calls

[hafot]

Dh had a very acrimonious divorce 7 years ago.
No love lost between them at all , and they hardly spoke over the years even though they have two kids .
But since me and Dh got married 6 month later ago everytime Dh phoned his kids or facetimes them she is always in the background shouting comments, friendly comments regarding whatever is mentioned in phone call.
She sent her regards to Dh last night regarding a family health issue .
I just don't know what's going on and I suspect Dh doesn't hate her as much as he has always maintained. Am I being paranoid ?

But since me and Dh got married 6 month later ago

What does this mean?

It's a good sign that they have gotten to the point that they can be amicable around the kids. It's far better for them then mum and dad constantly biting each others heads off. It also makes co parenting alot easier.
In general my DP and his exW are on good terms so when MIL passed she sent her condolences. She even offered to bring DSS to the hospital for extra visits prior to her passing. It made things alot easier on my DP as she was very understanding regarding a bit of extra flexibility.

This is far preferable to when there not getting on and DP is in a bad mood because exW has had a go at him over something.

Maybe she feels more secure and happy now he is married? I feel far more comfortable around my ex when he is in a relationship and he isnt flirting with me