Location: Pennsylvania

So, I (M23) am one of eight beneficiaries of my great-grandmother's estate. She passed a few years ago, and we've just been waiting for the lawyers to get settled up and let us know what's going on. At first, my great-uncle was the executor of the living trust, then he died. After my uncle's death, my cousin became the executor, and another uncle who was a beneficiary died. In the original living trust, it was written that if anyone passed, their share be redistributed to the remaining beneficiaries. It was probably written this way because the first uncle's wife was disliked by my grandmother, and the second uncle who passed left home a long time ago and didn't speak to my grandmother.

A couple months ago, all the beneficiaries received a check for $12,500 and a letter stating that the check was a partial disbursement of our share of my grandma's estate, and that the lawyer's office would work on finalizing the estate and that we'd have to come in to sign a Family Settlement Agreement. On the letter, the first deceased uncle's wife was listed as a beneficiary, and the second deceased uncle's name was on there as well (I'm assuming for his wife or kids) which goes against the original trust. My sister contacted my cousin to see what was going on because the lawyer's office is terrible at getting back to us. He said that he hasn't heard anything, but we should only expect about $1,000 more. This is confusing to me as my grandmother had investments, savings, and her house sold for $200,000. I know I have to maintain expectations, but it's confusing to me. As long as I get a fair share with everyone else, I'm okay whatever happens, but my sisters and I have a suspicion that we're being taken for a ride. That brings me to my questions:

What should I expect/look for, specifically in regards to a Family Settlement Agreement to make sure I (and my sisters) are not getting screwed?

I know I will get info. about how much was used to pay bills, debts, the executor etc. but is it standard practice to know how much everyone else is getting?

My aunt (first deceased uncle's wife, only related through marriage) also took a truck that belonged to my grandmother, nothing fancy, but an old truck that she had told every grandkid would belong to them one day. She just took the keys to the truck when my mom and sister were cleaning my grandma's house. They didn't say anything because my uncle was still alive at the time, and really sick. What can we do about that?

I hope there's enough details there, and I'd be happy to expand on anything. My little sister and I are both broke college students, so we want to make sure that we get treated fairly. Our grandmother would have wanted us to use any money she left us to help better our futures.