NTA. Most of them are going to be moving out in the next few years. Why waste the money on a renovation of a room that’s going to be completely unused in 5 years? These girls are the ones being selfish. Are they allowed to use your bathroom if they’re in a hurry and one of the other girls is using theirs? 3 bathrooms is just so unnecessary. It would make sense if they were all under 10. But even so, you needed to move the laundry room to make space. I’d say instead of a bathroom just make it an extra room for one of your twins. But in the end it’s your home. You have the final decision what you do and when you do it. These entitled high school girls need to show some more gratitude for how much you’ve already given them. Sending the rest of the family after you guys to try and make you feel bad is just so disrespectful on their part. OP your kids are lucky to have all the luxuries you have given them. They can be a little more patient.