What a little sweet-heart,I too thank you for taking her in,what could have happened to her if you didn't I don't even want to think of.
Introducing a kitten to a laid back male cat,should not be a problem,a little hissing at first,but I am sure they'll both be ok,a slow intro is important.
When I got my youngest(now 9yrs old)he took to my older tabbie right off and they were pals from that day on.
"The cruelest animal is the Human animal"
3 kitties,Rocky(r.i.p my boy),Chico,Vinnie