In the 1770’s it was not unusual to send young children (ages 10 to 12) to Europe for schooling (William Smith, for example) or, like William Temple Franklin, for someone to spent almost their entire adult life in Europe. If they were original born in Virginia and had children while in Europe, their children would be citizens of Virginia, even if the children grew up in Europe.
Obviously, if it could be shown that they were active loyalist that could affect their claim.