This mother just wanted to give a happy home to an adorable but troubled foster girl - it nearly destroyed her sanity...

This mother just wanted to give a happy home to an adorable but troubled foster girl - it nearly destroyed her sanity...

Sometimes, the spine-tingling scream of her four-year-old son William still echoes through Colette Smith's mind, and she vividly recalls how she found him sobbing in the kitchen as he cradled the broken body of his pet guinea pig.