The beneficiary and next of kin are two different things and don't have to be the same person.

TBH, a lawyer is well worth it in this situation. They will sort all of this out for you, deal with creditors, discover all her bank accounts, who she owes money to, file her taxes (that will have to be done), etc. My brother is a lawyer, and when my father died, we still hired a lawyer, if that tells you anything. And my father only had a total net worth of maybe $50K when he died, not some complicated estate. The lawyer was worth his weight in gold. It will probably cost less than you think and will be paid by the estate. Ours ended up saving us more money than we paid to him. For example, her funeral expenses can be paid by the estate instead of by you. My grandmother was still alive when my dad died, which made her next of kin, not us. That ended up saving us a bunch of money on taxes, since my grandmother was in her 90s with no income.