I am staying with an elderly relative while their usual carer is on holiday. This has been planned for months and agreed by dh. Youngest dd is 11 and has some mild sn, it can be difficult getting her organised and out the door for school in the morning. Since I agreed to do this respite, dh has got a new job, its not stressful and they are very flexible, but being newish he wants to be in early, make a good impression etc. For the last few mornings (at my request) older dd (age 18) has been helping by getting dd11 up and keeping on top of her so dh can get her to school on time. She has also been supervising her homework etc. All good. However, Dh has recently started a class on a thursday morning before work, a leisure activity, not work related, and he doesn't like to miss it. However dd18 has a big event tomorrow night, she will basically be out all day and most of the night, probably until 4/5 am, and I suggested that perhaps she could lie in tomorrow in preparation for her long night. Dh is very annoyed that he will have to manage dd11 on his own and miss his class.
Aibu to say that dd18 has been very good to help out and that dh should step up tomorrow?