Tracey is Michael's twin sister. Due to an adoption at birth, she became a Canadian Citizen as she was adopted to a Canadian family living in Vancouver, BC. She doesn't know anything about the rest of her family even though Jessica lives in Bellevue, WA (by air, it's only an hour - or 4 hours by train).
When she does find out about her family, she's a truck driver (the big rigs) living in Burnaby, BC. Her brother gets to ride with her on the maiden voyage of her brand new (owner-operator) truck to Montreal, Toronto, Winnipeg, and back to North Vancouver.