well.....after working in the bar biz on and off for umpteen years, everything from topless to college to corporate, i can tell you this....you should have fired her the first time she mouthed off to you......... from the little i have gathered from your two posts, it sounds like she might be a bit of a mother hen in the place to the other workers, like she has an "im untouchable" attitude...... the fastest way to get the attention and respect of those you want to keep is to get rid of her, your going to loose respect and control very fast if you dont make a move fast......
whatever you do, dont do it during a shift and give her a chance to make a scene and rally the customers to her favorite drinking hole afterwards.....call her monday morning, and tell her to come and pick up her last check before lunch time, also tell her at this time she is barred from the premises effective 12 noon.....then it will go one of two ways...
1- she wont show and will tell you to just mail it to her
2- she will come in...and this will go one of two ways.....
a- she comes in, you sit and talk...she leaves looking for a job
b- she comes in, raises all holy hell, she leaves looking for a job......
important part is, the place is closed and no one is around to see whatever happens.....
trust me, she has been there for 10+ years, its time for a new fresh face, harsh to say yes, and maybe even a cruel way to be..... but its the truth, you replace her with a younger fresher prettier face, i doubt very seriously you will notice any difference in the bottom line like stated before...
and if her replacement is flirty and personable enough, she wont need to be a great bartender to get started.....she can learn as she goes, its the best way to break a new one in any way......
i worked for a place that hires only fresh out of bartending school, and then throws them to the wolves so to say during a party event working a beer tub or outside shots bar