On Alcatraz buildings like the 64 building, officers club, and the parade grounds. The 64 building was were the officers family lived and the parade grounds where the kids played in Al Capone Does My Shirts.
In The book, the kids of Alcatraz took a ferry to School on the Mainland. They also took the ferry back to Alcatraz.
In the book the convicts on Alcatraz played baseball when they were allowed in the rec yard. The convicts would not play it that much because they were not always in the rec yard.
In real life places like the 64 building, parade grounds and officers club were on Alcatraz. I found my info on https://www.wikiwand.com/en/Alcatraz_Federal_Penitentiary#/Warden's_House
In real life the kids of Alcatraz took the ferry to and from school every school day because the school was on the mainland. I found my research on http://www.ournationalparks.us/west/san-francisco-bay-area/alcatraz_was_unique_home_for_prison_staff_families/
In real life the convicts of Alcatraz did play baseball and other games when they were in the rec yard. I found my facts on https://www.nps.gov/alca/learn/historyculture/baseball-on-the-rock.htm