My daughters are traveling around Europe for a month and want to spend two nights in Zadar at the end of June. They are having trouble finding recommendations for a place to stay. They would like something near the water. They will not have a car.

I was just in Croatia. There are no hotels in old town Zadar. Just stand by the taxi stand or bus stop in town, and women of all ages will ask you if you need a place to stay. Look online for "sobe" or apartments. They are everywhere, and seem quite reputable. Everything in the old town is close to the water. Don't worry about no car - the buses in Croatia are very good, and the ferries are great if their schedule fits yours.

I wasn't crazy about Zadar. Split, Pula and Sibenik were much nicer. Zadar was much more modern than the others and had lost a lot of its old charm. My personal opinion, tho.

Any other recommendations?

I stayed at the hotel zagreb in Zadar, not on the water but very nice.

Zadar was bombed heavily in WWII, sadly it was reportedly as beautiful as other Croatian cities prior to that.
Zadar is reportedly undergoing a bit of a rebirth. I was last there in 2003 and only briefly at that.
Private accomodations are easy to come by throughout Croatia. They can always head to the tourist office if something doesn't pop up at the bus station.