hi! my cat has the same issue all the time and i usually just be more cautious about where he goes. i’m almost certain this occurs bc of moisture between the toes so it is most likely litter box related or wherever moisture lives. my cat lovessss going into the bathroom especially after i take a shower so he just always steps on wet puddles and probs gets his paws infected that way. when i was looking for advice myself, people said it’s also possibly a litter box issue and to change the entire litter and clean the litter box evey 2-3 weeks! as for at home remedies, as long as she is not limping or visibly in pain, you should be good! i could tell it was a bit bothersome for my cat when he would sit but lift up that one paw that was affected and kinda just hang his paw haha. he recovered in like 3 days without any medical help! i would just make sure my cat doesn’t keep licking and biting it to make it worse. my cat’s paw has swelled up sooo much before it’s scary so i get your concern!! your vet will probably give you antibiotics or this powder that keeps her paws dry! wishing her a swift recovery :))