Twins I have knows:
Patricia, known as
Patsy, and
Gillian;
Patricia, known as
Pat, and
Jane;
Janine and Adre;
Ian and
Lisa; a few others that I don't recall or only remember one of.
I would never inflict
Frankie on a domestic pet. On a human child, it's most unfortunate.
Fenton is lnfn trendoid, and
Francis would have been a pleasant surprise but
Frankie ... no. And I dislike matching initials on siblings, let alone twins.
Louis is fine; I much prefer
Lewis, which solves all the pronunciation problems at a stroke.
Luca has a fem look to it: I know it isn't, but
Lucas or
Luke would have been preferable.
For girl twins, I'd like
Alice and
Laura; for boys,
Ian and
Gareth.