Should I Remove My Para From My Room

I teach Kinder and I went into teaching with a para seeing them as "the other teacher" and I let her help me make decisions and the like. However, since it is my classroom I have the final say. So we have been disagreeing on behavior lately (ie. students who are the students of the week, if they are getting in trouble or I'm having to get on them they will lose the title for the remainder of the week) and she has been reporting me (I just found out the other day) to the principal who only told me a couple of the things that she has said about me to her.

The other day was the last strike for the principal when she came in crying about how I'm changing the behavior rules to go to the treasure box THAT I PAY FOR AND STOCK! My students have adopted this idea that if they don't do work they will still get rewarded at the end of the week. I've had some even cry about doing their work so they don't have to do it. So I installed a new way to go to the treasure box after my other ways were failing miserably. That they would go to the treasure box if they got their work done on an interactive fun game on their computers during their morning and center time (about half of the units they were supposed to get or higher). This comes after there is data showing the students struggling in the class are those who are choosing not to practice these skills in class. She disagreed with this and then went on to tell me that I'm being a bad teacher if I do this to which I ignored.

The next day she went to the principal who called me in and we talked about the situation and she was completely on my side and asked me if I wanted to work with her for the remainder of the school year, to which I said I don't have a problem. Well, WHILE I WAS GONE she is seen on camera (district-wide camera they installed in every classroom) GIVING THE STUDENTS WHO DIDN'T GO TO THE TREASURE BOX SOMETHING (I reported it as candy and she told me it was just a sticker that she made that had encouraging words on them) First, they cannot read encouraging words so to them it's a gift. I told my principal obviously that she was defying my rule and I don't want her in my classroom, and told my para that I can no longer trust her because she has lost respect for my authority in the classroom and she went against me.

The whole purpose of not giving the kids who didn't do their work anything from the treasure box is to reward those who do their work and encourage those kids to come back next week and work hard! And the incentive worked for 3 of the kids who usually don't do their work, they did their work and achieved well OVER their required units.

I'm just seeking advice to see, did I overstep in wanting her out of my classroom or did I do the right thing?

Also, a treasure box is not required to have. Other teachers incentivize with candy pieces and computer time instead of movie time at the end of the day. I just use a treasure box.