In the suit, filed Feb. 5 in Gloucester County, Cornwell had asked that the fund, with an estimated value of $100,000, be split between the parents and administered separately.
After jointly overseeing the fund, Pasquale had his former wife's name removed from the Fulton Bank account where it was held without telling her, prompting the legal action, according to the suit.
Cornwell also asked in the lawsuit that she be included in any decision-making for her daughter's tombstone.
Autumn, her brother, and her sister lived primarily with their father in Clayton.
Two teenage brothers have been charged in Autumn's slaying and prosecutors are seeking to have them tried as adults.
Autumn was reported missing the night of Oct. 20 after she did not return to her father's home on time, prompting a vast search by officials and residents.
Her body was found two nights later about a mile away inside a curbside recycling bin next to the home where the two suspects lived.
The case is being handled by the Camden County Prosecutor's Office after a lawyer representing Anthony Pasquale filed notice of plans for a lawsuit against the Gloucester County Prosecutor's Office over its handling of the case.
Paul Spadafora, Autumn's great-uncle and godfather, had questioned whether the girl would still be alive had the search been conducted differently.
But in announcing it was transferring the case to Camden County on Feb. 6, the Gloucester County Prosecutor's Office said that "all indications are" that Autumn was killed hours before she was reported missing.
The girl, a bicycling enthusiast, had gone to the defendants' home, ostensibly to trade bike parts.
Contact Joseph Gambardello at 856-779-3844 or jgambardello@phillynews.com.