Sue,
I think I can finally respond now! My internet connection has been terrible since last week.
First of all, congratulations and "thank you" for agreeing to try your hand at fostering.
Secondly, just from my limited experience, I have had no problems with any foster dog that has come through our doorway. Of course, both of my girls (I should say "all three" since Murphy is now here, fulltime) are very sweet, docile dogs, and are very submissive to any other dog that is around them. But there has never been any problem. I just have walked in with the "visitor" and once all the tail sniffing is overwith, everyone has been fine. I hope your luck will be as good as mine has been.
Keep us posted!!!

Logan