For your daughter, if water is an issue, perhaps help her learn to drink water out of a water bottle while riding.
Breaks vary. For a longer through-ride, I like to stop every 30 to 50 miles or so. So, fo a short ride of < 50 miles, there may not be a need to take a break. Or, I may stop at a restroom or water fountain to refill or purge.
But, I also do a lot of round trip utility cycling, so for my typical ride, I might ride 10 miles, then stop, then another 5 to 10 miles. With a few stops, hitting 30 to 50 miles total.