This is long, but I'll try and keep it brief. I just need somewhere to write this down because it's eating me up inside.
Me and DH have two DS. DS1 is coming up to 3 and has been on the ASD pathway since he was very small. Formal Diagnosis made a few months ago.
DS2 is 5 months old.
My worries and anxiety lie with DH's mother. So I guess this is a MIL thread.
She has yet to meet DS2. She's only met DS1 a handful of times. She doesn't like me, for reasons unknown. Hasn't liked me since before children were even involved (have known DH since we were 11)
There's been some failed attempt at plans since DS2 was born, her not turning up, her trying to make plans on the days we've already got plans, and vice versa.
During this time, she's met up with DH four times 'to talk' during these talks, DH tells her how much it hurts that she doesn't seem interested in our children, but is telling his Sister how upset she is that she's not involved. Afterwards there's promises to be better etc
We can't go visit her and her house is extremely unsafe for DS1 (open fire etc) and it'd cause so many meltdowns and anxiety on all our parts.
DH's Sister is forever on his back about making plans with their Mum, she gets quite angry but can't seem to understand that it's not all DH's fault, and that their Mum is in the wrong too sometimes. She didn't call or respond to DH's texts/calls on Christmas Day, didn't ask how our children's day went, absolutely nothing.
This now brings us to last Friday night.
Day before my birthday (which MIL knows)
Me and DH have been out together in the daytime whilst DS1 was at nursery and DS2 was with my Mum. It was a lovely day. The evening plan was to have DS2 to stay the night at my Mums, and us settle DS1 at home (my Mums house isn't safe enough for DS1 to spend time there without us)
My brother was then going to come and babysit for an hour whilst me and DH went to the local pub. Pretty unheard of and I was really excited about it!
We arrive home at 5:30pm, DS1 is exhausted and DH was planning on bathing him and putting him straight to bed. When we pull up, MIL is on the doorstep with presents. We haven't heard from her since NYE so this was quite a shock.
I say: 'Oh hello! Erm, DS2 isn't here right now, he's at my Mums because we were going out for my birthday but..'
And before I could even get in the front door, she'd flung the presents at DH and walked off shouting 'Fine!!' With her hands in the air. We both shouted for her to come back but she didn't.
My Mum literally lives around the corner, we would have easily been able to organise MIL seeing him even she'd even given us a chance to finish our sentence. She didn't even give me time to get in the house and get her Christmas presents.
DH caught up with her at the train station, by this time DS1 was in full meltdown mode from the shouting and DH leaving so abruptly meaning he didn't even begin to settle down till 7pm. So it was 8pm before he got to bed (2 hours later than it should have been)
Me and DH were exhausted and just on edge after all that, so didn't end up going out at all. DH said when he spoke to her at the station she told him she'd tried to ring but he didn't answer (his phone had died) so he asked why she didn't just call me (I've given her my number countless times so that she could make plans through me. She's never once phoned or answered any of my texts) she refused to reply to that.
She wouldn't come back to the house and just got on the train and left. There's been no contact since.
I just don't know what to do. DH doesn't want to talk about it, SIL is on my back about getting DH to phone their Mum, DH has told her to stop countless times, but it falls on deaf ears. I've stopped asking DH to call or text her, because right now I'm trying not to care. The times she has visited in the past she's completely ignored me in my own home.
It's making me so anxious though, I don't like there being tension in the family, and somehow I feel this is all my fault. DH assures me it's not, but I can't help feel that if it wasn't for me and our DC's, he'd still have a good relationship with his mother. Which is the way I'm pretty sure MIL feels 
I feel sorry for her over Friday night, it must have been upsetting, but at the same time she didn't even give us a chance to explain.
AIBU for worrying about this relationship? Or shall I just pretend this isn't happening and see how it pans out?
Sorry this is so long