Worried friend and her baby are being abused

I am a new mom and have met several mom friends via baby groups in the neighbourhood. One mom has made some worrying comments about her husband. Including that he controls her finances, that he insists the baby only sleeps on his chest (despite it being 2 now), and has said a few times that he's been 'really mad' at her for little things like not doing laundry or forgetting to put groceries away. I'm not at all close with her and most comments have been shared with me by other mom friends, so I haven't had opportunities to really get her to open up.

I don't see them often now I'm back at work but I bumped into all of them recently. The baby is really quite withdrawn and is acting quite aggressively to my baby and some of my other friend's babies. Pushing them over and grabbing them but without any provocation and with a really blank look in their eye. The dad was really rude to the mom (swearing at her for something minor) and was really off with us.

I'm concerned that he's very controlling and possibly abusing the mom or both of them. I have no evidence other than what she's shared, the changes in the baby, and a horrible gut feeling when I met him for the first time (you know when you just KNOW someone is a bad person??). Any advice on what I can do? Or are my hands tied without anything concrete to go on? Their baby and mine use the same childcare - could I raise my concerns with the provider anonymously?