help- one rat bit the other's tail

i wasn't looking when it happened, but skunk and olive were in their cage. i had the door open and was switching some bedding for clean towels when suddenly, olive approached me with a bite about halfway down her tail! i'm assuming it was skunk (though i didn't hear a fight or anything) since matilda was up in a hammock at this time, and that it just happened immediately before she came to me. it's a small bite, just on the surface, and the skin's broken but it's not bleeding. it's not really swollen or crooked, either. she doesn't actually seem to care much about it- i was able to pick her up and handle her tail like normal.

needless to say, i separated the two cages (their big cage was two cages put together) and skunk is in solitary. it's weird, they have been living together relatively peacefully in the two spliced-together wire cages for the last few days/nights, with what i thought were normal rat scuffles at night and cuddling during the day. this seems unprecedented, especially toward olive.

my main question is, what should i do to treat this? i really don't think it's so bad that it requires a vet- i can't really afford it, frankly, unless the situation's something i can't handle at home, and i'm kind of stranded here until evening anyway, until evening, without transportation. should i clean it? should i leave her be? i cleaned it a little with water just so i could get a better look at exactly how bad it was.

also, i hate to say this, but i think maybe skunk's too old to deal with babies in her cage. she mostly just wants to lay around. should i let her continue to live alone, interacting only during playtime while i'm watching closely?

what do you guys think? i'd really appreciate any help here.