I don't recall Chelsea having gone on a trip like this when she was in Sidwell, but it could have happened. I do remember as she got older, especially while at Stanford, that she seemed to miss an awful lot of school because of trips she took with her mother and/or father. We could never understand how she could take off so much time from her studies and keep her grades up.
Nothing seems to have changed with Chelsea, only now everything seems to come before real work.