Can bio mom say what we do at our house with my step kids?

they have 2 kids together.his son told her about 2 years ago that i ed him, really just a tap (it was b/c he hit my 2 year old) then ss told her that the bruise on his arm was from me, which it wasn't. dad is afraid to discipline the kids bc of their mom. we had supervised visits, but it was dropped pending nothing happened between june and august, which it didn't. Last weekend was our time.he works nights and i work days. so had to have someone drop them off to her. we got my mom to do it.well his ex was enraged, yelling at my mom for not knowing her or something. I could have dropped them off the her, but she didnt want to wait an extra 30 minutes, because the kids have strict schedules, she just makes life hard on everyone here. she told him that my mom raised me and she didn't trust her.she even said that 55 year old lady's can abuse kids too.like my mom is a bad mom too.so we had it out once again, she always says that me and her don't have kids together. next visit we went swimming and they supposedly got sunburns, so she told him she was taking him back to court, then changed her mind.