Hi and welcome to JA. I am Ray and will be the expert helping you today.
You need to monitor this situation to make sure you are treated fairly by the executor/trustee sister.
The executor/trustee has a fiduciary duty to you to treat you fairly, to account for funds, etc.She can be removed if this is not occurring.
You also have right here to legally challenge the will and the trust if you feel there was undue influence or the deceased parties lacked mental capacity at time they wrote the will.This is called a will and trust contest.
It may be possible to have the will and trust held to not be valid in which case laws of intestacy give you both equal rights, including right to be appointed administrator under court supervision.
You may want to strongly consider your own lawyer here to challenge the will/trust and make sure your rights are protected.It may be possible to have you added through the courts to co trustee and co executor.That may be ordered by the courts in any such challenge and filing.
Reference to contesting the trust/will here.
I appreciate the chance to help you today.Please let me know if you have more follow up.Thanks again.