Hello XXXXXXXX,
I think you aren't doing anything illegal, but I do think a guardianship/conservatorship is the best way to go. This will allow you legally to get medical help for your mom, and to make sure that no "outsiders" question what you and your sister are doing.
I have provided a link to the Virginia department for aging telling all about Guardianships and helpful information. I do not agree that the money would go to lawyer fees. One simple set of documents is all you need, but you may be able to get free help. Check this website:
Good luck.
Hello again,
If your sister has a joint account with your mother, then all of the funds are at your sister's disposal and can be given to you for your mother's benefit, or bills to be paid. Nothing you told me seems to be at all illegal. But, as I said, I think a better way to do things would be to get a guardianship/conservatorship.
Attorney
Attorney at Law