Looks like some updated info coming out in the initial investigation stages-
from the above article:

Girl who went overboard on Disney Dream cruise fell 'backward through a porthole'
Investigators are looking into what happened before two passengers went overboard on the Disney Dream.
www.usatoday.com
from the above article:
Investigators are disputing rumors about a father and daughter who were rescued after going overboard on a Disney Cruise ship over the weekend.
The Broward County Sheriff’s Office told CBS News Miami the “little girl was not being held, as erroneously reported on some social media sites,” following chatter about the dad placing her on the ship’s railing.