K.C.
It doesn't seem to me like your daughter is doing too much. She has a lot of play time at home and some fun activities to look forward to each week.
My son has preschool three mornings each week (finishing at 11:30). He has swimming lessons one afternoon, soccer practice one afternoon and soccer games on Saturdays. Each of those activities only takes up about one hour.
We also do a weekly playgroup one morning a week and random other playdates as they come up. Sometimes I feel like we're too busy and overscheduled, but then whenever we are just home for too many days in a row, we all go crazy. He is happy when he gets outside and has time to play at the park or the pool.