I am typing on a broken keyboard so bare with me and i apoligize for anything misspelled or just wrong lol its a hit or miss with this so thank you.Its also kinda everywhere so i apoligize in advance. So i am a SM to a 7yr old girl. My husband ex wife is a very mean muniplitative vindictive and just all around difficult person. Well for the past 5 years i have had to learn how to not only be a step parent but also how to deal with this crazy BM. I lovge kids its always been something i care for i just have a natural motherly insticnt that ive had sense i started babysitting when i was 8 you know. But anyway co parenting is something that we have always struggled with. She dosent seem to see his side of things. over the years she has moved past hating me for being in her daughters life as a motherly figure. but she still cant get past the fact that she feels that her feeling and decisions are not only the only thing that matters but that she is the only one right. My husband has gotten to the point that he no longer even says when something is bothering her or tries to be to involved because hes not even listened to or respected enough to take in account what he has asked?  Now BM and i are able to to communicate better but him and her not so much. Well she reccently came at me in the manner of her wishing he would be more 50/50 with parenting but when i try to explain to her that she has to allow him to if she wants him to. I guess i should note that we have 50/50 custody 50/50 on everything. BM just takes it on herself to make all the decsions without his opinion first. He didnt get a say in what school she went to when we asked about registering for K we were told she was already registered here and thats where she was going even though that was one of the schools we had put on our list of no when looking for schools. We did have knowledge of her doc of dentist or anything like that because she wouldnt allow us. She wouldnt even give him a copy of he Birth certificate and SSC. After 5 years of being around 2018 was the first year we knew about what medical places she went to. 

So anyhow she wants him to be more 50/50 but she wont allow him to do so, i dont see how to get past that with her when she is so stuborn. She is just a poor me person and im not im just thinking about whats best for my SD and trying to get on the same page. Its hard to because im trying to be adult about things and because my husband works long hours 6 days a week me and my SD spend so much time together so i plan lots of things and i jsut do alot when it comes to her so me a BM have to communicate alot but its hard when im constantly being told how Because i dont have kids of my own i dont understand what it feels like to love them and to care about them and wanting to be involved and such and its very upsetting to me and probably is the #1 thing that pushes my buttons and she knows that. but its so NOT true becaue i love her as y own and more then anything she is my world and to be told how because shes not mine pretty much my feelings dont matter are wrong. Im not trying to take her place as a mother im just trying to be my best for her when she is at our house. She just wants to communicate between her and my husband but literally every time they do it turns into yelling at eachother because as soon as he disagrees its out the window in argguing. If he agrees easy convo but when it dosent go the way she wants its a yelling match. She refuses to not be in control of everything no matter who it effects.If he tries to ask for her to not do something its you worry about your house ill worry about mine. COOL i agree to a point, if it involves SD then he can worry about it otherwise i agree. But one example is when my husband found out that BM ex was still watching and taking and picking SD up from school he requested that she pleaase find other way because he wasnt convortable with it she told him no.Keep in mind the ex that she was living with for 3 years then now she is living with a new BF. So he requested it because she didnt want my SD being exposed to such a confusing potential awkward place. He was immediatley shut down she didnt even have enough respect to hear him out or finish his sentence. just like ugh

Anyway now with a little backround. whats a good way to coparent with come one like this or is it that case where no matter what its probably not going to happen? Also how do i communicate with her. how are we supposed to communicate with someone who everything is one sided? or am i being ridiculous?