Augumentative

I was talking to Tilly about going on an eighth grade field trip. The class is going to a local camp area for hot dogs and burgers and fun. The school is asking for chaperones, servers, etc. Tilly asked her older sister, who is married with children, to be a chaperone. Her sister, Samantha, only works a few days at a local fast food restaurant. Her sister's husband, Joe, has recently become unemployed, but I hope that by the time that this field trip occurs, he will be employed again. They have a three year old little boy. who Samantha watches during the day. I told Tilly that she should tell Samantha that she would love to have her as a chaperone, but that she would understand if Samantha couldn't commit to being a chaperone. A campground with approximately 300 eighth grade students running around, would create a difficult time for Samantha to keep a good eye on the toddler and hopefully her husband will have a job by then. This prompted an arguement. Tilly responded that EVERYONE loved Todd. I told her that even if everyone loved him, this was a time for the eighth grade to blow off steam and many would get tired of watching him and that Samantha would be harried trying to help and watch him at the same time. I was talking quitely and reasonably, but Tilly only wanted to see her side. She said she wasn't taking the offer away. I told her she shouldn't take it away, but tell Samantha that she understood that it might not be a good thing to have to find a babysitter or worry about the toddler and that if Samantha felt that she couldn't make it that Tilly would understand. I told Tilly since she had asked and since she wanted Sam to come that she should say something like that to give her sister an out without her sister thinking she was going to hurt her. Instead of reason I got an arguement. Anything that isn't what Tilly wants does not get any consideration. It is time for Tilly to grow up and think about others and not just herself. The more I tried to reason with her the more defensive she got. Sometimes I get tired of beating my head against this wall.