I'm in a similar position as you though my home value is less than half that of yours. That said, I'll pass along what my attorney told me when I set up a will in case any of it applies to you.

My IRA and 401k have beneficiary designations where I chose an animal charity as my primary beneficiary in each of those accounts. What that means then is that it would not need to go through probate and the money will go directly to the charity I've designated.

I'm still unsure what to do about the house because that's a little more complicated. Maybe somebody else has some advice..

As for your sister, again this is what my lawyer told me regarding my brother is to leave him a token account as opposed to leaving him completely out of the will. If bro were to contest it, he wouldn't really have a legal leg to stand on, but he advised me it would be safer to leave him a little something as opposed to nothing. Maybe there's some personal item or something like that that you could designate for her?

Anyway, kudos to you for your savings and investment and for leaving your money to charity. I feel kinship with you. 🙏