The brownish possums shown on the show are Australian Brushtail Possoms that aren't known to be carriers of diseases. They won't bite or harm people, and actually have a natural resistance to rabies. The ones that bite are a different species called Opossums, and they are grey.
While texting, Samantha's messages show up in green which would actually be Georgie's "responses".
Highly unlikely that a 14 year old who volunteers at an animal rescue would stick her fingers into the cage of a strange animal.