Legal Question in Wills and Trusts in Pennsylvania

Was an estate probated? If so, then creditors had to file claims within the deadline. If no estate was ever probated, then they had 1-4 years to sue. There is a prohibition on claims being asserted more than 1 year after death, but you have to read it in conjunction with another statute.

You are wrong about joint accounts. Joint accounts usually pass 100% to the survivor. I don't know why money was distributed to remaining heirs. However, joint bank accounts are not a probate asset. So none of the money in the joint account would go into an estate unless there is some provision that allowed an executor to lay claim to the money, like in North Carolina. I am not aware of anything similar in PA though.

The best thing is for your wife to go and get a consult with a probate law attorney who practices in the county/state where the estate for her mother would be probated and review what was done and whether there is any obligation on the part of the children to contribute to the payment of this bill.

You ask if paying the bill would cause future problems. Like what? I don't know how paying a bill would cause a problem but I do not want to render an opinion on this because I do not know all the facts and I have not seen the will or other charges. That is why your wife needs to sit down with a probate attorney to review this.