As you may well have noticed, there are lots of couples out here looking for a bi female. "Standing out from the crowd" can be quite a challenge, and many have reported a lack of success.
What I have noticed is that most of the posts are just too generic - "need a bi female as a friend and for sex" doesn't really tell anyone much about what they are looking for beyond a gender and capability for sex.
Is it ok if this person has other relationships, or is married? What about smoking - are you smokers? Is it ok if she is? If she already has children?
I'm sure you get the idea.
Good luck on your hunt.
"Listen, or your tongue will make you deaf." - Native American Proverb