Question about purchasing mixed class tickets for a family...

Okay long story short, but I want to Home Alone it. Not leave my kids behind, but put them in coach. I have a rheumatoid arthritis and need a more comfortable seat for a cross country flight. Kids are 14 and 16.

Is it possible to book 2 first-class tickets for my husband and I and 2 main tickets for the kids on the same reservation? We don't want to get separated at all if there is an issue or flight change. There is one layover in the flight we are considering booking.

TIA.