Legal Question in Real Estate Law in Illinois

There's an old saying in the law: "past consideration is no consideration." In your case that would mean that unless there's something very unusual you have not told us, look, you took care of them and paid some expenses but got to live there, and that was the "deal". So, very unlikely. Now if you paid out of pocket for last illness and funeral expenses, for those things you may have a charge (reimbursement right) against the estate. As to the power of attorney, normally they expire once the grantor of the power (mom in this case) dies unless there was some specific interest that can be enforced and is stated in the grant. For a clearer and more precise answer, take the POA and all of the other information about the arrangement to an attorney to review, but very possibly the best you might be able to get is some voluntary reimbursement or consideration from your sibs. And unless your sibs are thankful you took care of them so they didn't have to, well, watch for sparks.....