How do you act when a coworker you helped trained starts bossing you around? And being rude to you with huge attitude.

Does your job pay well? Otherwise, welcome to the working world! Almost all jobs come with this sort of baggage. I would only leave if I found something that pays better. Having a good Boss means much more than those other petty things. Stay out of them and just remember, this is a job for 8 hours a day, not your home. 

maybe you should talk to your manager about it and let them leave , also, i would be thankful you have a job, wish i did

It never happened to me. I trained my men and they did what they were supposed to do. If anyone tried to boss me around I would have given him a bad eval and transferred him to another shop.

Oh I can so identify with that!!! We may be in different countries but that happens here too... I used to work in a non-office environment and LOVED all the people I worked with..we all got on and we all supported each other.. I then started work in an office environment and I have to say all the office politics and backbiting I find so difficult...I really don't like nastiness like that.. people can be so disloyal.. and i find it depressing and hard to cope with... so i hear you on that one.. 

You shouldn't have to be the one to leave because of their bad behaviour... but I know how it feels and I get why you feel it's time to leave... sometimes it's easier than putting up with the rubbish... 

I hope it all works out for you 

You trained her so she's under you.  What can she do if you just ignore her bossiness or even just laugh at her?  In my first good job I was new in an office of old-timers.  They all thought they could give me assignments; I would keep a pad of paper on my desk, pat it, and just say, "It's on my list."  I worked at my own rate and never got to the bottom of that list so they stopped asking.  
Then a new girl arrived who was boinking the boss and thought she was the new queen of the office.  She gave me assignments too although she was way under me in rank.  Eventually she poisoned herself with her own venom and, finally, they were both reassigned to lower positions elsewhere because they were found out.  Ha ha.  Thing right themselves, then they go wrong again, then they right themselves again.  That's life.  Hang in there and good luck.

     It doesn't seem to be an environment
that I would invest any time with,
unless it paid really good
or good tips to make it worthwhile
to deal with the bad stuff.
     Find your inner peace
in your heart and stay there while you work.
Nothing else will affect you. 
     Let all people be as they are
Find your Bliss 
and embrace it...
.....and observe the rest.

It sounds like you need to train them again then...

It is a problem just ignore the person.

I don't blame you for not wanting to join the band wagon and start gossiping.  Know that they are so bored with their own lives, they find the need to nip-pick at someone elses.  If they would like to help with someone elses life, they should offer.  Talking, blaming, and shaming others just isn't right.
As far as finding a new job, I would still try and work on this one.  Obviously you have the smarts and know how to make it work.  You are in a position to call the shots for yourself.  Make that be known and say, "Hey, you know, I'm important to this whole function too.  I am valuable and I have feelings.  I do care about how you work with me.  Please, let's all stop placing judgement and start making this a great place where we all can have fun and make the time go quickly. Let's Rock n' Roll!"