They join English teenagers Lily May Humphreys (16) and Annabell Fuller (15) on an eight-strong team for the contest at Quaker Ridge in New York from June 8-10.
Mehaffey and England’s Alice Hewson will make their second appearances for GB&I, after featuring in the winning side at Dún Laoghaire in 2016. They are joined by India Clyburn, Sophie Lamb and 18-year-old Scot Shannon McWilliam.
Elaine Farquharson-Black, who will captain GB&I for the second time, said: “There have been a number of players throughout Great Britain and Ireland who have been in impressive form recently and it was a difficult decision to select only eight.
“The players selected will now have a wonderful opportunity to perform on the international stage in one of the world’s most prestigious events and I’m sure that they will give their very best, as we attempt to retain the trophy against a talented team from the United States.”
Ireland’s Leona Maguire, who is second in the world amateur rankings, ruled herself out of contention for selection by choosing to turn professional next month, while England’s Isobel Wardle, who was also named in the provisional squad, has decided to focus on her school exams.