Are we in the wrong?

My boyfriend has kids with his ex. I have raised them when we first got together 2 years ago mom left state came back.... He has custody she has visitation every other weekend and Fridays when he works till he gets off for his weekends. She is now throwing a fit that he won't let her see them more and all this. In the summer they stay till Monday at her house till she works. She works nights. Then has let them go on vacation with her. Even though in papers it doesnt state he has to. Holidays we are attempting to split. In our state most people trick or treat on satuday if it lands on sunday.... we are offering her to take them satuday to trick or treat so we can get kids to bed at a decent time on Halloween because of school the next day. If we mess up their schedule even by a half an hour we're screwed they act out. We have tries to talk to her about splitting the other holidays. She is throwing a fit. She had them last Christmas eve and is demanding them this Christmas eve and all of Christmas break. She is refusing to pay the full child support amount and is throwing many different tantrums about all of. Now she is saying she is only getting to see the kids when it's convenient for him... Mind you we are supposed to have a week notice if plans chance. She wanted them longer on his Friday..... she asked that day and we agreed as long as she fed them dinner. She decided she wasn't going to keep the kids longer. Even though we didn't have to we was letting her. We explained if she talked to us we can work something out if she has plans and wants to keep them longer on his fridays.... but if we have plans and can't do it we will tell her again it is his weekends and if we make plans with the kid's we explained we would tell her. But again she said it was only when it's convenient for him..... are we in the wrong?? I'm seriously done trying with her.

You have a court order…follow it. You don’t HAVE to give her anything. Not sure why people think you do. The courts already decided what are the kids best interest…and it’s not her.
Also who cares about child support. Child/spousal support never should have been a thing.