I mean at it's most basic, tarot is essentially just a random number generator for creating a story.
Ordinary playing cards can and historically have been used for 'divination' like this, so there's no reason Uno cards couldn't, you just have to assign a narrative element to each card.
If I wasn't in so much pain right now (endo), this would be a really fun to dive into. I might jot this down actually, it could be my October project.
Thanks. It's a bastard. Sending solidarity to your sister! (And tell her to get an electric blanket if she finds heat helpful for the pain, and doesn't already have one!)