The USA Water Polo home page for the 2015 Junior Olympics is here: http://www.usawaterpolo.org/juniorolympics/.
From that page you’ll be able to find the schedule, results, and other information. The girls play in Session Two from July 30 to August 2.
Some important pages include:
Schedules – you can review the schedules online or download to view in Microsoft Excel (look for the Download icon in the lower right); note that schedules may change before the games begin so be sure to check again and/or buy a printed program at the tournament
Tickets – tickets can be bought online in advance; early-bird discount pricing ends July 15 ($5 off per ticket)