That's the question going around both Britain and the United States because of her uncanny resemblance to the late actor!
Although Peter Boyle, famous for his role on the TV hit show "Everybody Loves Raymond" and who died two years ago, was listed as being born in Morristown, Pennsylvania, but his parents were from Scotland and THE SAME AREA as Susan.
Meanwhile, Susan was raised by her Aunt, Fanny Boyle.
A source close to Susan Boyle says that she always claimed she had an actor brother in Hollywood and that their dad was on the telly many years ago as "Chuck Wagon Pete" a Philadelphia TV personality from 1951-1963 who, among many other things, played the Western-show host Chuck Wagon Pete, and hosted the afterschool children's program, Uncle Pete Presents the Little Rascals, which showed vintage Little Rascals and Three Stooges comedy shorts and Popeye cartoons.
As most regular movie goers remember, in the movie "The Dream Team" Peter Boyle burst forth in song with his rendition of "Hit The Road Jack". Most had never heard Boyle except the high shrill voice as the Monster in Young Frankenstein.
However, both were amazing performances.
If true, it's too bad Peter didn't get to see his sister's beautiful performance this past week. I'm sure he would have given that big handsome grin and said, "Hey, that's my little sis!"