my mother.

*back story*
I have a two year old son from an ex, my ex has nothing to do with him and never has no matter how many times over tried.
I've  been married a year to an amazing guy who is in the process of adopting my son.
I also live an hour away from my whole family but will be moving out of state once my husbands new orders are in (army)
My mom hates this because she already dislikes us living anhour away.
Also after I had my son I dated a guy from high school for a month.
(If you're still reading this bless)
Anyways, my husband is on what's called CQ today so I took my son to see my mom. While I was at her house she looked up my sons bio dads whole family on facebook because she "wants to see what they have to say about" is moving away.(none of them care at all)
Then she looked up the guy I dated after I had my son saying how much my son looks like him and then messages him and his mother asking if they're willing to take a DNA test to prove his really the father.
I left as soon as I found this out and now I'm at a lost of words.
She was going to get to keep my son over night on Friday but now I'm scared to even let her do that.
Should I reach out to both my exs and see how they're gonna handled this, should I tell my mother off, and should I keep this from my husband?
And before you ask my exs are 21 and 20 and my husband & I are 26 and 22..