Staci,
If it makes you feel any better, both Honey and Lilly came home to me at six weeks old. Of course, Honey has her issues, but considering the environment she came from, she was probably better off leaving when she did!! Although I have learned in the last year or so that it is better to keep them with "mom" until they are 8 weeks old.
Both of my girls have adjusted fine, and have become quite the well-behaved babies. I know your Keegan will do the same. Just love her and keep those warm clothes out, so you can jump into them and take her outside for a quick break in the cold nights!!
Kylie....you will get used to this new intruder. I'll be you and Keegan will become fast friends!!