OP, I am in exactly the opposite position to you. My dm desperately wanted to leave the house to me, the youngest and only girl of 4 dcs, because we were far away the poorest and have 3 dcs to support, but my oldest sibling, who doesn't need the money, but likes high living (eg he will only fly first class) forced her to change her will not once but twice, threatening her that he would not attend her funeral or say prayers for her after she was dead (important in my religion). She was heartbroken but felt she had no choice, but must have told me (and everyone round her) literally hundreds of times that she really wanted to leave the house to me, but he wouldn't allow it.
As I stood to benefit, I didn't feel it was right for me to get involved, so just told her it was up to her who she left things to and I wanted her alive not her house.
In the event, my eldest sibling didn't bother to attend her funeral, or even dial into the online version.
I now feel so bad my mother didn't get to leave her house to who she wanted to - not only or even mainly for my own sake or my dcs, but because as a parent myself I know how important it was for her to feel that she was giving her daughter and grandchildren a roof over our heads that she knew we couldn't be able to afford to buy with only a quarter share of her house.
Respect your mother's wishes. She wants to die in peace knowing that all her children are financially secure. It's not about loving you less. That she's spent so much time with you and your dcs shows she loves you. She just doesn't want to die not knowing if all her children will be financially secure.
Enjoy your mother's company while she's still here. And don't be jealous of your siblings' relative poverty - instead be grateful for your considerable comfort (nanny and all).
When your mother is dead, she's dead for ever. Enjoy her company now.
If you pressure your mother over this, you prevent your mother from dying in peace knowing she has helped the children who need it most. And you risk spoiling your relationship with your siblings too (I won't ever see or forgive my brother for forcing my mother to change her will to benefit him, against her wishes).
At the end of the day, it's your mother's money. And you don't need it. Let your mother leave her house to whoever she wants to leave it to. Or you don't really love her - just her money.