When to call CPS?

My ex husband and I have been divorced for about six years and we have a 9 year old daughter who is with me majority of the time. He lives a couple hours away and lives with his long time GF (5-6 years?). She has two kids around my daughters age that she shares 50/50 custody with.

I’ve witnessed her berate the kids, be extremely condescending, and dismiss their feelings completely, but hey, I’m no saint as a parent! However, over the years, I’ve heard some concerning things and now that I have a friend whose going through some stuff where she’s having to report things to CPS and the sheriff, it’s making me wonder if I haven’t done enough to protect my daughter.

A long time ago, when my daughter was maybe 6ish, she was throwing a tantrum and the “stepmom” put her outside the house in her underwear because she didn’t want her to wake up the other kids who were napping. I talked to my ex and he said “she was standing by the pocket door the whole time watching her” as though that made it less crappy. Anyway, I’ve more recently heard of things like the stepmom uses hot sauce and a paddle as punishment to her kids, never to mine. She has them do wall sits as punishment or hold a book over their heads. Borderline abusive but is it? By the way, my daughter expresses fear towards her because of these punishments.

Recently after I told my ex about my daughter getting a bad grade in math, he talked about it in front of the other kids who made fun of her later. I told my ex, who told my daughter that he asked the kids about it, who conveniently forgot, and stepmom was condescending in the way she questioned my daughter.

Then, a couple visits ago, my daughter told me that she was asked to make her bed. So she did. Later during bedtime, stepmom told her (while my daughter was in the bed) that her bed was a garbage can and she was going to take her blanket. My daughter told her “But I’m in the bed” and response was “look at (name of other child)’s bed. It’s perfect.” My daughter said she was super cold so she grabbed a robe to use as a blanket. Later stepmom came to check on her daughter because she was coughing and told my daughter “take off that robe now!” So she did. The other daughter offered for mine to share the bed with her so she wasn’t cold, but my daughter was worried stepmom would come in, so she went back in her bed and said she tried snuggling with her stuffed animals to stay warm 😧 It sounded intentionally malicious, not like normal discipline.

In another conversation, my daughter mentioned that stepmom’s son was sitting and crying on the ground, and then my daughter said she didn’t see what happened but was told by the other girl that stepmom had her foot on the boys stomach and he was now lying down and crying.

I just... custody and court is complicated and we have been getting along so well but some of the stuff I’ve heard lately is concerning and I don’t know how to address it.

Options:

1. Call CPS and stir the pot but they likely won’t do anything anyway.

2. Talk to my ex. He will defend the GF and brush off or minimize what I was told.

3. Talk to my ex and GF together. She’s extremely defensive and the conversation will become a fight. They aren’t mature so they won’t be civil about other things when there’s tension.

4. Do nothing. I fear that my daughter may not tell me everything that happens because she thinks it’s normal and she shouldn’t be afraid of any of her parents.

What would you do?