Oh Spork, I am so sorry for your loss!
Both of my parents have recently passed away and we are still working on settling the estate. My parents set up a trust and everything is supposed you be divided equally. Problem is, their documents are so oversimplified that they are open to interpretation. During all this drama, I have been reflecting on the fact (Spoiler Alert: don't worry, this isn't the pity party it's going to seem to be at first.) that there is simply no way that things can ever be equal.
Hmmm, let's see, I paid for my own college, bought my own car and eventually my own home without parental assistance. I had cancer in my early twenties and moved back home for a few months while i underwent treatment. I had medical insurance, but paid my portion of the bills (20%, but boy, it added up) by myself. When I finally got married for the first time four years ago, we eloped, so no OOP to my parents. In fact, it was only after they were gone that I realized that they didn't send a wedding gift of any kind, even though they were thrilled with my choice of spouse, primarily because he fixed a lot of stuff for them, lol. I have no children, so no gifts to my kids or contributions to college or whatever. All of my other five sibs received the kinds of help I described, in varying amounts.
You know what? I am damn proud that I had the skill set and drive that I did not need their help. And I know they were proud of me. There is no way that the scales will ever balance perfectly. I am happy to be in a position where it simply does not matter. I know I can fend for myself, thanks to skills they taught me and my own tenacity. When I receive my "share", whatever it turns out to be, I think most of it will go to charity and to helping a couple of cousins that I wish my folks had remembered in their will.
Be happy that you know how to be successful without their help. One of my sisters is going to fritter away all of "her share", and she has no other savings. She even stole money from them, thus lowering everyone's "share". I wouldn't change places with her for anything.
Life isn't fair, and no one is obligated to leave anyone anything. The sooner you realize this and understand that you can count on yourself to make your way in this world, the easier it will be to let go of the idea of equality. You're a mustachian, you really can figure it out on your own. You'll be fine, no matter what your parents/grandparents/any relative decides to do with their money.
I realize this is a me, me, my story, but I do hope it helps. Choosing bitterness is not a good way to go.