This is regarding my question about my sister putting in a petition for guardian and estate of our mother.

The roles of caregiver, power of attorney over financial matters, power of attorney over health care decisions (all while someone is alive) and representative for the estate of someone who passes away are each distinct roles. Not sure from this which one(s) your sister is playing. Sometimes people who are the caregivers or help out in other matters such as taking care of the finances receive greater portions of an estate in thanks for what they have done.

Estate rules are governed by State law so the full answer to your question depends on where your mom lives. Generally she has no legal requirement to leave you anything in her will. Your legal protection depends on the estate documents your mom creates or the laws of the state if she has none. In most states you do not have a right to see those documents until after your mom passes. At that time the estate will be divided according to certain rules and if you are entitled to any portion then you will have rights to be protected.

If your sister has full guardianship then she has an obligation to use your mom's resources for your mom's benefit. If your mom is staying at her house then some of your mom's resources will be going to your sister. Can she find ways to financially enrich herself? Possibly, Do you have any recourse? Yes, but hard to prove unless blatantly obvious. Can you demand an accounting of the expenditures, a listing of assets, etc to make sure that your mom's estate is being protected? Sometimes yes, but that depends on the State rules. You should contact an attorney in your mom's State specifically about those questions.