[quote breadrollz]@farfetched I don't know why you keep mentioning what happened in your family as I would argue it's not the norm.
I honestly wonder how some people brains work when a poster says "I feel hurt after finding out I've been excluded from inheritance" & the responses are "don't be grabby", "it's none of your business". 😆 it's batshit [/quote]
I haven't argued it's 'the norm'. 
I have argued that it sounds very similar to this situation, only in this situation I represent the people whose voices we don't get to hear in the OP's story, namely the other siblings and the dm.
It's precisely because a very similar (not identical but similar) situation played out in my family, but from a different angle, that I feel able to present the other views the OP doesn't seem to have considered, and the risks involved in encouraging her dm to change her will to suit the OP, given the OP has made it clear she doesn't need the money.
In short, she risks hurting her dm and spoiling their very close relationship. And she risks harming her relationship with her siblings.
It was suggested upthread I had therapy. Well, a) I did - and it was my therapist's horrified reaction to this story and her stated wish that someone had stood up for my mum and helped her to be firm in the face of my db's pressure to change her will to suit him (I didn't feel I could do this, as I stood to gain), that made me realise how much my dm suffered from this awful pressure to change her will. And b) by the same token, I suggest the OP has therapy to address what are clearly deep underlying issues about being unloved, which have led her to frame the will in this way.
From everything the OP has posted, I see no signs the OP is loved less than her siblings. I see a dm trying her hardest to be scrupulously fair, and ensure all her dcs end up equally comfortable and well-provided for.
If anything, the fact she's planning to leave ALL her personal possessions to the OP would suggest to me that the OP is secretly her favourite (although unsurprisingly, she would be reluctant to state that).
What I find really distasteful is that all these conversations are being had while the dm is still alive, well, healthy and in full possession of her faculties. To all those saying 'but the OP's situation may change, she might need the money', well, so might the dm's situation change. She might need to spend it all on care costs, and the OP's siblings could get nothing, while she gets all the sentimental items.
OP, stop having designs on your dm's money - especially as you don't actually need it - and try to enjoy your dm's remaining years.
I would give every penny I inherited back just to get another day with my lovely dm. 
Your dm won't be here for ever, OP, and when she's not, what will bring you comfort is not the money but knowing you helped make her last years happier, and got to spend so much time with her. The money doesn't matter - it's not life-changing for you. The time (and the personal possessions left only to you) do matter. Enjoy those precious last years.