Isabella was the daughter of Guido.
When Amy went undercover to open the trap door for the Eleventh Doctor, Rory Williams and Guido, she met Isabella. When the Doctor and his friends were trapped, Isabella showed them the way out but couldn't leave because the sun burnt her skin - despite not being a full Saturnynian yet. Rosanna deemed her a traitor, and punished her by pushing her into the canal. Thinking she wished to drown her, Isabella swam. Seconds later, however, she was pulled under by Rosanna's children, and was devoured.