Baby-oil heiress Casey Johnson, who died last week at age 30, was laid to rest this morning during a private funeral in New Jersey.

The small gathering, which took place in New Brunswick, NJ, included Nicky Hilton, who is the godmother to Johnson’s adopted baby daughter Ava, People magazine reported on its Web site.

PHOTOS: CASEY JOHNSON

The Johnson & Johnson heiress, who was engaged to reality TV star Tila Tequila, was found dead in her LA home on Jan. 4.

She suffered from diabetes, TMZ.com reported, but no cause of death has been determined.

The family said donations in Johnson’s memory can be made to the Casey Johnson Memorial at the Juvenile Diabetes Research Foundation.