I sent my 12 and 15 year old girls to bed tonight without dinner.

Before moving in with me, my sisters lived with our brother and before that, our parents. They grew up with no rules or structure and was allowed to sleep whenever they wanted, eat whatever they wanted, and do whatever they wanted. They spent a lot of time playing video games and watching random videos online all the while performing horribly in school. Since they've moved in, my husband and I have implemented rules, chores, and routines for them. And since we've implemented all of these things their grades have improved tremendously from d's and f's to a's, b's, and c's. We are extremely proud of that and have rewarded them accordingly. However, It's been almost six months and we are still having to remind them every day to do their chores, take a shower, wash their hands before dinner, clean up after themselves, etc. If I don't remind them to eat, they will forget to eat until it's much too late. For example on the weekend they will have breakfast, completely skip lunch and then be starving by 4pm when dinner is around the corner. Tonight after they finished their homework, they began watching stuff on the computer in their room. We hardly give them any screen time but since it was Friday and they finished their homework, I said it'd be fine on the condition that they don't lose track of time. My husband and I were downstairs when my 7 year old sister came down to see if dinner was ready. She ate with us and went back upstairs. We waited and waited and the rest of them never came down once to check if dinner was ready so we packed up the food and put it away. My husband and I stayed downstairs to watch tv and finally at 8:40pm one of the twins came down because she was hungry. Their bedtime is at 9! So we told her to go back upstairs and get ready for bed explaining why there would be no dinner tonight. 

You guys! We have dinner every night around 6pm as a family. EVERY NIGHT. They are 12 and 15 year olds. I feel like I shouldn't have to keep reminding them of these things. We are trying to teach them responsibility and they've come a long way (which we did praise them for) but boy do we have a long way to go. 

What I want to know is, was that cruel of me and my husband to deny them dinner and send them off to bed? We just want to teach them a valuable lesson. Why do I feel so horrible tho?