Babysitting Blues

Since I am in the community play, I have to have a lot of rehearsals. We open our first show the first week of September. It is very exciting. My issue with this is that I have to spend money on a babysitter. My poor mother in law has the shingles so she is unavailable. Well to be neighborly I hired the assistance of my neighbor's daughter. She has experience babysitting and I needed her in a pinch. I asked her what a going rate a babysitter charges these days for two children? Since this was my first time enlisting the help of a teenager, I didn't know what the going rate was. Does anyone have any ideas. I joked around that she could not make more hourly than me :) Well I had to make the decision because she was indecisive. So I paid her $6.00 and hour for two kids. I thought that was pretty reasonable because she didn't have to feed them, just entertain them. She loves my kids and they are fun, sometimes rowdy. I ended up paying her $12.00 each night I had rehearsal. This week it ended up being $36.00. Yikes!!! I now have to readjust my budget to help me keep on track since this is an unexpected expense. Luckily I had the money. My question is, how much is reasonable? Did I pay too much, or too little. FYI minimum wage here is $7.15 so I think she did alright. I also think I may be overpaying her, but I could be wrong.