Future mother in law- need advice....

Ok, so I know that famously sometimes you are not supposed to get on but I really don't know what else to do as it goes alot deeper than that and just wanted some unbiased opinions...
To cut a long story short, when I was uni and doing my teacher training course I lived with fmi and step father in law. I could see it coming a long way off them getting in debt investing in stupid things living in a house they couldn't afford but they wouldn't listen to anyone. So now for obvious reasons they can't help out with the wedding which is fine but I have tried very very hardest to get her involved in other ways such as taking her along to wedding fayres, showing her pictures of ideas and texting her with updates as soon as they are done. My mum and dad have even tried to invite them both round for dinner for ages.
But she just does not seem at all interested in anything! Which is extremely out of character, not only that she is happy to take money off my h2b and I to help with a vet bill (£500) and we bought her a new washing machine. It hurts me so much that she can not get excited about our day when she gets overly excited about other peoples lives etc.
I just feel really sorry for h2b as she doesn't even listen or pay attention when we do tell her, she sent me a message yesterday asking what time she had to be at the venue! Hello! it's her eldest sons wedding! She asked me also if we had a photographer when I've taken his portfolio round to show her and also asked if we are having a marquee when I have shown her the pictures and went round to hers on the way back from the venue to tell her about it!! I have offered to go shopping with her for her outfit but she text me the other day saying she had bought it from a catalogue (not fitting in the with the colours really.) at one point she also came round for dinner whilst h2b and I were cutting out hearts for place names and she promptly pushed them onto the floor to make space so she could sit down! You would think she may offer to help! She has arranged a hen day at her place for me as she can't afford to come away which is fair enough but keeps telling me who is coming so u don't get a choice in the matter! (all her family) HELP!!!!
We asked her to be a witness the other day so she felt like she had something to do but immediately asked who the other one was straight afterwards!
I honestly don't know how to make this situation easier as I am beginning to resent her a little!

To be honest I think she's at least showing an interest asking questions even if she can't remember the exact details and has gone to the effort of arranging a hen night for you even if it's not exactly what you'd have organised yourself.

My h2b's mum is in a similar situation - lives with her partner and the two of them are up to their eyeballs in debt - with new cars and motorbikes and designer watches and new computers they can't afford to pay for! She's shown no interest in the wedding whatsoever, says she can't afford to come to the hen weekend and can't afford to buy an outfit for the wedding. She has never once asked about the wedding, we've tried to tell her about things to include her but we've both been completely ignored. I get on fine with her otherwise but with eight weeks to go she knows only the date and the rough venue and I doubt that'll change. I don't think it's worth stressing out about. I could get upset that she doesn't care but it's her problem and I have other people who I can talk to about the day. It's our wedding - I'd think most people are bored to tears with my plans so I don't expect it to be everyone's priority!

I know it's difficult but I'd try to appreciate the effort your mil2b is making rather than slate her for what she isn't doing. You don't want to start married life resenting the in-laws already.

Thanks, I wouldn't mind but it's just so out of character for her! We always tell her stuff she never asks I have tried to involve her so much as she has 3 sons and thought she might appreciate it as she doesnt have a daughter to share this stuff with. When we were showing her our honeymoon stuff she was more interested in what was happening in eastendrs! Other family members have started to notice it too! I don't know, I guess il just have to accept that she is being different in this case :.(

Could you ask other family members to mention to her that she seems out of sorts and see if they can get a reason out of her for it?

If it's out of character then maybe it's worth having a chat with her to see if there's anything she's worried about or if something's on her mind? Maybe she's trying not to pry too much incase you think she's interfering.

My mil2b is just plain selfish 100% of the time - she shows no interest in h2b ever - just gives him grief if he mentions spending time with my family (h2b has said my mums been more like a mum to him than his own in the last few years). So we didn't really expect anything different - which I suppose is why I'm past caring. It just upsets me to see h2b so sad about what she's doing (or not doing).

That's exactly how I feel! I think my h2b is used to coming second but my parents have been so supportive and helpful with everything which just highlights how little she is doing and I don't even mean money wise. Just feel sad for h2b I think that's all it boils down to :.(

It's a really horrible situation. We were at my mum and dads yesterday and they have decided to pay for my wedding dress now on top of the contribution they've already given us, plus they then bought us a bed we liked as a wedding present. But your right I think every time they do something like that H2B thinks it highlights what his parents aren't doing. And it's not just money and it's not just about the wedding.

My mum just treats him like one of her own - if we go for dinner she's always got his favourite desert, even just the fact she makes us dinner whenever we're round - in the five years we've been together his mum has cooked for us once and has been in our flat twice to visit even though she comes up to where we stay at least once a fortnight to shop.

It's just hard to know what to do when I have no experience of coming from a family who don't seem to care about each other or treat one another with love and respect. I've told h2b we'll be each others family from now on and he likes that. But I just feel really sad every time I see his mum hurt him again.