How to get copy of my moms finances?

If they spent all her money how are YOU responsible for the funeral? Let them handle the funeral. Costs can often be very low if you go to funeral homes and discuss the circumstances. You really cannot request copy of finances. At the point of your mother dying someone will have to file for probate if there are any funds, pay remaining bills, etc. Let that ALSO be them. Basically they have already ripped off your Mom. She will soon be at peace and no longer care. So sorry, but it is now too late to do anything about this unless some estate is left; sounds as though there may not be. If sister and her dauhter's friend file probate, that is a public document, and you can proceed from there.

Without a POA you will not be able to get copies of her finances and now its too late because Mom is not able to assign one.

Does Mom have a Will. If so and your Executor, you will be able to handle Moms finances then. A short certificate (thats what its called in my state, may be different in another) saying u can handle Moms finances. If no will, you maybe able to become an Administrator. Then you can get copies of her accounts and see where the money went. Maybe sister felt Mom should pay for living with her and sister doing the caring. In the end, you will at least know where the money went.

If Mom is cremated the cost is low. Where I live its $2300. If you have no service or viewing there is no cost there. If there is a lot, there will be a cost for opening it. Some places allow the person to be put in a lot of a LO who has already passed, but there maybe a cost there too. Or just hold onto the urn. You can have just a graveside service. You can have a Memorial later on. Rent a venue have some food and celebrate her life. Or just immediate family getting together for lunch or a dinner. I am finding that families now tend to go simple. Funerals are actually closer for them. Viewings just for friends to offer condolences.