AITAH for thinking my mom deserves nothing

My dad recently passed, leaving behind barely anything. He had like $35 in his bank account, no 401ks, no life insurance, no savings, just monthly social security payments as income. Before he passed he signed over his only vehicle to my uncle (totally fine don’t care less I have to deal with and he owed him some money). My parents divorced around 20 years ago, my mom went to work one day and didn’t come home when my brother and I were older teenagers and shit just spiraled after that with them breaking up and going through a rough divorce. Fast forward to now, my dad left behind a house which they bought together in 1999 and were divorced in 2006ish. In their divorce paperwork it states my mom is entitled to 1/3 of the net profits of the sale of the house. There’s no time cap, no conditions, no further statements other than that. In 2016 she signed a quick sale deed “selling” the property to my dad for $1. Which he followed that deed transfer with refinancing the house under a hardship program to catch up back taxes and mortgage payments at the time. Because that document doesn’t specifically state something along the lines of also waiving any prior agreements from the divorce paperwork she would be entitled to 1/3 of the net profits from the sale of the house. Unless she signs a document stating she’s signing over her 1/3 to my brother and I.

What will happen is this - the house will go up sale. The difference from the sale price and what was remaining on the mortgage will be the “profit” - my mother would get 1:3 of whatever that is THEN out of the remaining 2/3 - I will be reimbursed any money I’ve put out so far for the estate (garbage, electricity etc), cremation / death certificates expenses from the funeral home, retainer for the lawyers to go through the executor process and probate, plus 1 % for being the executor and any remaining balance due to the lawyer over the retainer I initially put down, the realtor will get 3% of the sale price, any taxes and anything else along with house closing will be paid, along with any other debts my father had like credit cards, a personal loan he was paying on and anything else that comes out of probate. After all of that then my brother and I would split the remaining “profit” (if there is anything) 50/50.

At first I had said my mom wasn’t getting anything as I thought the paper she signed in 2016 for the quick deed signed all that off, when I mentioned that to her she got a little heated and threatened to get her own lawyer and I told her I wasn’t talking about it and everyone needed to cool down as I was already dealing with so much as it hadn’t even been a week since he passed. A little while later she messaged me saying she wasn’t going to lose my brother and I over it, and it wasn’t worth it.

Flash forward to today - I messaged her all this explanation of how the profit breakdown would be dispersed if she decided she didn’t want to sign over her “1/3” and said she wants to talk to me before she decides anything on what she wants to do. I get the law is the law and I can’t argue or change it, but am I the asshole for believing it should just be my brother and I splitting everything in the end from my father’s estate and she should sign over the house fully to us?