Sounds like things are going pretty well. I brought a kitten into a house with 3 older neutered males and a dog last winter. She spent the first couple of weeks seperated from them and then she started spending short periods of time in the house with everybody. There was a bit of hissing and snarling but not much and they even put up quite well with her going into heat!! I think I took about 2 months total to where she was living in the house 24/7. There's the odd bit of hissing still but that's mostly when she's trying to get the old men to play!! One cat will play and wrestle with her but the other two just hiss and smack her
If you take a towel or something you had in the crate with her, and just put it close to where your resident cat spends time, he'll get more used to her smell. Also make sure to have an extra litter box so they each have their own.