How long is it acceptable to use a provider for references when I haven't seen her in a few months?  I have tried on 2 separate occasions to make appointments with this provider but she was unavailable both times.  

Just don't want to seem like I'm taking advantage of her.

You are "using references" to see a woman you have seen before, from the same woman? Once verified, you should be good to go.

If I understand what you are saying, most women you have seen before should be willing to see you again if the session went well.  

Six months is a time limit I have heard from providers to give references to a different provider you want to see.

If she is not available, she is either busy or doesn't want to see you. Often times schedules do not match up.

Don't really know what you mean by " taking advantage of her."

And what they will supply as a reference, but a lot of ladies will say 3 months or 6 months max, so that is probably a good rule to follow. I once used a 4 year old reference and it was accepted, but that is definitely not the norm!

Sorry I'm blonde and don't get the post.........in the USA do you ask providers for references then...wow how bizarre.