older one has outgrown our weekend documentary night. younger one is heartbroken

we've done a documentary every weekend since the girls were small. animals, space, the odd travel one. this saturday the older one announced she's 'too old for it' and went to her room with a book. the younger one sat through the whole whale film with us and asked twice if akka was angry with her. she isn't, she's just 10. not sure whether to let the night go, change what we watch so the older one has a reason to come back, or let them take turns picking. or keep it for the younger one and leave the door open. what did you do when one kid outgrew a family thing the other still loves