New Kitten Feels Threatened?

I recently received a 5 week old kitten from my daughter whom I live with. I have my own living quarters in the upstairs so the kitten stays with me most of the time. There are 2 female adult cats, one is older and spayed, the 1 year old is not, as well as a boxer who likes to play with cats, and a beagle who is very old and doesn't bother anyone. I have slowly introduced them to each other and there was no aggression shown from the resident cats, just some harmless hissing, with some growling from the younger cat.

The kitten just can't seem to warm up to any of them, and I have slowly introduced her to them, first by holding her and putting her near them so they could see each other and did this off and on for a couple of weeks before letting her loose around them. The younger female is curious and watches the kitten, hisses at her, but is not aggressive, the older cat could care less, yet the kitten hisses at them and runs the other way, and will not socialize with them at all. If she runs into one of the dogs she does the same with them.

We are giving her more time in the main house to get used to the others, but she is still not comfortable around them, she is now 10 weeks old. She has access to my room at these times so she can go to her refuge if needed. She's a very loving and adorable kitty, but very unsure around her housemates.

Is there anything else we can do to help this situation improve? We tried bringing the younger female to my room to see if that would help only to have the younger female start spraying in my room. She followed the kitten around, and the kitten actually did attempt to play with her when she was in her domain, but wouldn't play with her, hissed and backed away. These two cats are getting spayed shortly, will this improve the behavior?

By Skeeter Bug from Dallas, GA