Once you're a regular, there are other benefits besides a lower rate.  I won't go into details, hopefully you can figure it out on your own or others will get more specific.  

It doesn't always happen, but in a fair number of cases a gal will offer a discount in exchange for more frequent or longer visits.

If you bring it up however, it will turn her off

If you're taking the place of a client paying her full rate, there's a chance she might end up resenting you.  

What percentage are you contributing to her income? Does she have enough other regulars and/or volume that she would feel your absence financially?

What type of client are you? Are you more/less demanding than the average guy she sees? Does she already give you breaks in the form of extra time, or something else?  

Also, she needs to genuinely like your company (or at least be able to tolerate you well enough). Barring that, she needs to be broke and/or a very poor money manager. Sometimes that's more than enough... just not enough to make it long-lasting once she gets past her (current) financial crisis, lol

She reminds me that her rates have double and I am at her old rates

A client that asked for a discount.... isn't actually a good client... and I wont see him again after he even try to asked that question.  

A good client never discussed money, don't ask for discounts, have more intimate relationship, lady is being available with less notice than another client.... I definitely spend more time with my regulars (regulars as those that I see every week or every 2 weeks).

I dont think the lady get "discounts" on gas, make up, hotel, travel time... etc

Regulars get grandfathered rates.
Regulars get extra time.
Regulars get OTC time.
Regulars get menu items that others don't get.  

Not saying all regulars get all of these things or even one of these things, or if all providers offer any or all of these to their regulars. Just saying these are all possible and do happen occasionally between certain providers and certain clients. If you are lucky enough to get any of these benefits, be happy, be appreciatative, but don't ever expect or demand it, or feel entitled to it

Yeah it might happen, but it probably wont.  

 
There have been times that ladies have hinted at giving more at a later date, then they usually have an attitude next time around, as if you are there for something that you never asked for in the first place.

No discounts. Other than the initial p411 member discount I have listed. But that can only be used on the first meeting.