You are correct. No one else in the family has a Texas accent. Regards,
Regarding the Texas accent and who in the Bush family has it or doesn’t have it:
W is the only one in the family who both grew up in West Texas and returned there as a young man, married a West Texas gal, and lived in Texas for the next quarter century.
His parents were adults before they set foot in Midland, and public service has taken them out-of-state as much as they’ve lived here. His siblings moved away.
Other than travel and the Presidency, W has lived all but his first two years and his prep school/college years in Texas. What do you expect him to sound like?
I honestly think that George W. Bush draws more criticism for his authenticity than for anything else. The guy is who he is, and it rankles both the left and the right.