United Kingdom, April 22 -- Former child star Sophie Nyweide has died at the age of 24.

The actress - who played the daughter of Michelle Williams and Gael Garcia Bernal's characters in 2009 romantic drama 'Mammoth' - passed away in Bennington, Vermont, on 14 April, and her mother, former actress Shelly Gibson, told The Hollywood Reporter that "police there are investigating".

While no details about her death have been given, in an obituary posted on Legacy.com, Sophie's family told how she "self-medicated" to cope with "trauma and shame".

They wrote: "Sophie was a kind and trusting girl. Often this left her open to being taken advantage of by others.

"She wrote and drew voraciously, and much of this art depicts the depth she had, and...