One of my employees is getting married and quitting and has started to underperform, come late, wast

one of my employees is getting married and is moving to another state on the other coast. she is leaving the job in 2 weeks she has now started to come late and becoming inefficient regularly, when asked how should I treat you -she says - write me up. how should i tackle the situation without causing a revolt as the other employees see that this particular employee is taking undue advantage. should the employee be written up/fired or should i just let her enjoy the last two weeks and wait for her to quit?

One of my employees is getting married and quitting and has started to underperform, come late, waste time?headache

Pay her the two weeks and release her - this is a common practice since that person is in a sense a detriment to everyone else - unless you require her services to ensure a smooth transition of operations when she leaves - show her the door and yell out "Don't let the door hit ya where the good Lord split ya!"

One of my employees is getting married and quitting and has started to underperform, come late, waste time?paramount theater opera theater

pay her her last two weeks and show her the door.
If she is not doing you any good then get rid of her, anyone that has a problem with that doesn't care about your position in the company so why be concerned with theirs? Tell her that she has been a distraction and that you will do her a favor by giving her more time to deal with things in her personal life!
It is an ethical question. If she wished a good referance, talk to her about her tardiness and inefficiency. She already said "write me up", then do it. If it continues, write her up again. If necessary you may have to fire her, it is up to you as the employer to set the standard of work ethics in your business for all your employees.
Fire her. Her attitude is unacceptable. She needs to have it in her record that she was terminated from her last job for poor attitude and unsatisfactory performance, so the next time she goes looking for a job she won't be able to use you or your company as a reference. You're not being a hard@$$ -- she has earned a pink slip. Kick her to the curb.
I would sit her down and tell her that the consequences of being fired for due cause is no unemployment insurance payments and a black mark on her job history with no recomendations forthcoming. Then I would proceed to put a written reprimand in her personnel folder. Being a short-timer does not mean she can take advantage of her employer and fellow co-workers.
If she hasn't given her formal notice then fire her immediately and send her home with two weeks pay.

If she has given notice then firing her immediately probably isn't worth the trouble, I'd simply send her home for the remainder of her tenure with you. Pay her for the time but make it known that she won't be getting a reference from you. She's screwed when she tries to get another job and your other employees will understand downside to trying the same stunt.
Write her up/ fire her. Remember, this also serves as an example if another employee gives in their resignation in the future, you don't want your employees thinking that just because they are quitting they can act up. The whole point in the 2 weeks notice is so that you have time to find a replacement. If she's not working like she should, there is no reason for you to keep her there and pay her for it. You already gave her warning, and she had the audacity to respond that way. She'll regret her behavior when she loses 2 weeks pay.