Monster inlaw, or out of line daughter in law.

This is gunna be a long one and I'm rage typing so bare with the mistakes. Try to make your responses a little sensitive as I expect not everyone is going to agree with me.

Back story, I had 2 children when I met my now partner who I met 3 years ago, made it clear, they will and always will come first, he took it like a champ and has stopped up to be an amazing step father. His family stepped in and took my kids on like they were his own and all was good. We were great, never fought, never argued, he accepted my rocky past and whilst he struggled to understand my struggles from being in a previous DV relationship, he still did awesome. Fast forward a year on, we decided to try for a baby, and as expected, I fell pregnant straight away, we were all over the moon excited. Fast forward to 12 week scan, we were told our baby most like had trisomy 18 and wouldn't be compatible with life. We truly believed the doctors but went on for more testing. Which then discovered we got the boy my partner longed for, and he infact didn't have trisomy 18 and was completely healthy. We still had to get his heart checked again at 20 weeks. We both went together petrified for the worst, which turned out he had a perfect heart and all was good, until they checked his kidneys and to everyone's shock, there was a problem. At that stage, they can't tell what the problem was but asked us to come back at 28 weeks for an additional scan. All this did take a massive toll on our relationship, it was tough. He isn't a talker, doesn't show much emotion, whilst I do. We got through it none the less. Fast forward to the morning of the 28 week scan, I woke at around 3am with what I thought were Braxton hicks. Took pandol, got a heat pack and went back to sleep. Woke again at 5am and still in pain, had a shower, and a lay down waiting for my mil to come to watch the kids whilst we went to the scan. Well we never made it to the scan, half way to the hospital I realised, I wasn't experiencing Braxton hicks, I was in fact, in labour. My mum was present at my first 2 and my partner had no issue with her being there with the third. His mum stayed with the kids whilst I was in labour and gave birth. Which was pre planned as my mum would be present at the birth. Once the baby arrived, our parents swapped so mil could come meet baby and everything was okay. I accepted my baby would be in hospital a long time and I needed to go home,
I decided to got home day 2 as my other children needed me. I needed to go back to the hospital daily, express 3 hourly, and cry in between. I was shattered. I wanted to be home and at the hospital at the same time and I couldn't stretch myself. We really needed support. My mother in law went away to her holiday home (1hour away) the day after we had baby despite explaining how much help we needed. It didn't bother me
That much as I had friends and my mum who were all helping.
5 days after I had my son, I was taking my eldest to school, I wasn't coping like I usually would. My partner wa home and my mil was back and popped in. My house is generally spotless, but I had just cleaned the kitchen and my kids were running rings around me so all their toys were out. She then started at my partner "why's the house a mess" "why isn't she here" "is she shopping" he then told her to leave, told her she hasn't helped a bit and has no right to come into our home and criticise a few toys out. My partner and I don't lie, don't hide things so h told me what had happened. I was FUMING. How dare she in the midst of everything come make things harder. My partner was on leave at the time and she carried on saying I couldn't wait for him to go back to work, trying to cause friction between us. Why? Why would you do that to us when we have so much going on? Anyway, she stopped speaking to us. I bit my tongue and said nothing. Continued to update her on the baby progress with no reply. She turned his sisters into not speaking to us also and I slowly watched him go into a spiral down and to what I believed, he was depressed. We carried on though, fast forward to bringing our baby home!!! We finally hear from her. I was so pissed, she bailed when things were hard and wanted to come back for the fun bit? Hell no, but, again, bit my tongue for my partners sake and told her to come over. Things were normal from there, I was still so angry! And she became the monster inlaw. I never said a word about it, just accepted it made my partner happy, and that was that, one of his sister came round, the other was still distant, and as far as they were concerned, I was the issue. Fast forward nearly a year on. My partner and I had hit rock bottom, my eldest has a disability and it caused a lot of parenting difference between us. I was working in the evenings, he'd have the kids. I received a nasty text about my eldest and saw red. There were lots of issues, I was on my phone too much, he'd never talk about his feelings, I fell behind on housework, he'd favour his hand over me, no matter what it was we never tried to help eachother my curbing the problems, instead it would start with, I'm on my phone to much, and end in, I don't like your mum. When he sent a text about my eldest, we argued hard. He needed to vent and he called his mum whilst he was at work. He was in the wrong with what he said, I know that, he knows that. His mum called me, and started going on about my parenting, how I am as a housewife and everything. I asked her not to come over but ofcorse, she did. I was so angry that he opened the door for her to judge us as a whole. And that's just what he did, she'd show up, judge my parenting, tell me I wasn't cooking good enough, cleaning good enough, and it caused a lot of problems. My partner and I had so many issues, both of us, at fault, I am not perfect, neither is he. But I called it quits, told him I was done and walked out the door. His mum was over the moon. But then, 2 weeks later we decided we are going to try and work things out. She is fuming, keeps telling him I don't love him, I'm manipulating him, I'm using him. Even stopped so low as to stalk my Facebook and point out 1 guy who likes a lot of my photos and tried to say I was seeing him. Which backfired because my partner knows who it is and knows it's false. I'm ropable, her son is happy with me, we are happy as a family and she's just being impossible. She stepped into my children's lives for 3 years, called herself nan and doesn't want to see them anymore. Keeps telling my partner to come over with just the baby. I won't have it, f$&@ her. I told my partner I've always been supportive of his mum being in our lives but if she can't be support then she can fuck off. I have no problem with him seeing her but he isn't taking the baby. If she can't accept us as a whole, then she gets nothing. She can't pick and choose who she sees. My partner agrees with where I'm coming from and is supportive on it but I feel like a piece of shit. But if feel worse about my eldest two missing their "grandparents" whilst my younger one doesn't. I don't know what to do, I'm so angry right now. It's the baby's birthday in a couple of weeks and I'm deadset on her not coming.