The State Government and police will try to erase the posts.
The two pages have 35,000 followers, several of whom have contacted Crimestoppers.
Some vile comments and images already have been removed. But others remain on the sites dedicated to four-year-old Ayen Chol.
One post on a page described the pit bull-cross linked to the girl's death last Wednesday as a legend.
The Herald Sun has chosen not to detail the contents of other posts that have not been removed.
One racist comment triggered the responses: "I hope you get mauled by a dog, so you know what she had to go through!!!" and "Go die in a hole ... u heartless waste of space".
Relative Daniel Atem said the family was not aware of the shocking photos and posts until contacted by the Herald Sun.
"It's bad. It's not good," he said.
It is the latest incident of tribute pages of people who have died being vandalised. Minister for Crime Prevention Andrew McIntosh said he was outraged the girl's memory had been attacked by cyber ghouls.
"These comments are despicable and offensive," Mr McIntosh said.
"The Victorian Coalition Government will seek advice on any action that may be taken against the cowards who have sought to defile the memory of Ayen Chol using the supposed anonymity of the internet."
A Victoria Police spokeswoman said police would work with Facebook to try to have any offensive content removed.
A Facebook spokeswoman said the site wanted to express its sympathies to Ayen's family and friends.
"We are also deeply saddened that a few individuals have shown a complete lack of respect for this tribute page," she said.
She encouraged page administrators to remove offensive content from the pages they have created and ban unwelcome visitors.
Herald Sun
