Virginia has a one-term limit for governor. The lieutenant governor has always been the favorite to succeed the governor when that term expires. I'm certain that her plan is to run for governor when Youngkin's term expires. Plus, as another poster pointed out, it would be highly unusual to have a presidential candidate pick a running mate from the same state.
Doesn’t the U.S. Constitution say the President and Vice President *can’t* be from the same state? And it’s not surprising that Virginia restricts governors to one term, since among the many 13 Colonies’ beefs against the British was the excessive power of royal governors.