But wouldn't that mean that you and your SO would inherit these debts when she dies, and there's nothing you can do about this? That's truly awful :(.
If your dead aunt had a Mercedes 190SL, but also owes $200,000, you can either take both or nothing.
But yeah – they won't end up in debt themselves, unless they choose to.
It only really becomes an issue if you have a strong personal attachment to assets that have high monetary value, like e.g. perhaps your childhood home - otherwise it boils down to a financial consideration.