Dad passed away and being forced to give up insurance money

Hi all, title basically says it all. I’ll (Scottish) not state exactly how much is being given to me but it’s a pretty substantial amount which would see me through paying for university and put the majority down for a house. My dad passed relatively young in his 50’s and had life insurance and it is being halted between myself and my brother however my mum who I still live with is wanting both our shares. She never got anything out the insurance because she had some special role of which I can’t remember the name. I’ve agreed verbally to give her the money as she says she wants to pay off her mortgage and invest the rest and promised my brother and I would get it back when she passed. Basically all I want to know is: should I give her the money? and is it right to do so even tho it was promised to me? I’m not a greedy person I’m just confused whether this is the right move or not and I have aired any of this with my mum or my brother as she seems extremely keen for me to immediately move this money on to her