The amazing outdoors or the Fleas?

Hello, I need some advice...
I trained Lucky to walk on a harness, so I can safely take her for some outdoor pleasures... She does a great job walking, however: Both days I took her out, one day to the garden, and today to my neighbor's house, she came back with quite a few fleas...
My neighbor has 2 inside/outside cats, and I am pretty sure they are the culprits... Luckily the fleas die pretty quickly, I notice that in a couple of days they are all dead (she is treated with Revolution), but nonetheless... I hate that she has fleas for even a couple of days!
I live on the ground floor, so I doubt I will even be able to keep the house flea safe with the winter and all...
It is definitely a catch 22 - do I provide her with the great outdoors, or keep her 100% inside and away from the fleas? Is there anything I could spray her with before leaving the house that could protect her?
Thanks!

If she has revolution on she has all the protection she needs--adding anything would be an overdose to her.

Sadly it is a catch 22--I long to take Jack outside but know with all the cats in the neighbhorhood that there are fleas out there and I just can't do it!

Leslie

Even if she only had fleas on her for a couple of days, that has increased her chances of eating one and possibly getting worms. I don't mean to sound paranoid, but this is the main way that cats end up with worms so I don't take my girls outside anymore even on a leash because I have had worm troubles with them in the past and again now one of mine might have a tapeworm from eating a flea.