Abandoned kittens

Someone abandoned these two cuties out side our house a few days ago. I brought them in when they were soaking wet from the rain and shaking and I can't find the owners so I'm going to have to take them to the shelter :( I'd keep them but we have three full grown cats already all males and these two are girls I think sisters. The white and black one has road rash in her chin and the brown and white one has a broken tail 😞 the shelter won't put them down for having injuries? My SO says they'll be put down but I don't think they will because they're not terminal.