Phenomenon: Shannon and Dian Sites

Identical twins Shannon and Dian Sites were born in 1973, but unfortunately, Shannon would pass away soon after. At 9 a.m. in 1994, Dian was driving to work and felt Shannon's presence. It made her pull over and stop which was lucky for her. If she had not done this a truck would have scrapped the side of the car and likely would have ended up killing her. When there are lone twins or twinless twins it is said that sometimes the deceased twin becomes a guardian angel. 

Was Dian just lucky or was Shannon there to protect her sister?

SOURCES:

Unsolved Mysteries