Felicity Drumm, who lives in New Zealand, was Webster's second wife. He attempted to kill her in a staged car crash after murdering his first wife in a similar way five years earlier.
Webster, 52, a qualified nurse, murdered Claire Morris, 32, in a deliberate car crash in 1994 and fraudulently claimed more than 200,000 from insurance policies following her death.
He was convicted at the High Court in Glasgow of drugging her and driving the car in which she was a passenger off a remote road in Aberdeenshire, and starting a fire while she was unconscious in the vehicle. He was also found guilty of attempting to murder Ms Drumm, 50, in New Zealand in February 1999.
Ms Drumm said: "I felt so humiliated at the breathtaking extent of his deception and that I couldn't see it."
Ms Drumm said Webster started to drug her during their honeymoon. She said she started to notice a "bitter" taste to her food and would fall asleep for up to 36 hours. The sleepy spells continued when the couple moved to the UK, even when she was pregnant with their son, she said. "I can't even begin to describe how angry that makes me feel," she said.