My kids are in high school and on block scheduling. There is no way I would take them out of school for 7 days!
I would let your daughter stay with relatives. If you really want to have a family trip with all the children I would reschedule the trip to sometime when they're out of school.
Its very difficult to make up work once the kids are at high school level. If she's a straight A student that means she's either in honors or AP classes, which cover a lot of material in 90 minutes, not including all the homeworks (I have an honors/AP student). If she missess 7 days it will affect her grades. DD missed a week due to illness one year and it took her almost the entire semester to get all the work caught up and her grades dipped. She's never missed more than a day since. She says its too hard to get caught up.
Also, as another poster pointed out, the teachers may not be willing to let her make up the work if its an unexcused absence. How will she/you feel if she gets zeros on everything she missed?
I took my kids out of school in elementary without any problems but stopped once they hit middle school (we have block scheduling there to). If it were me I would reschedule the trip for when they're out of school.