Nat!
Penelope?
Pee
Guinevere?
Guin or [name_f]Evie[/name_f]
Matilda?
Tilda (or [name_u]Mattie[/name_u])
Wilhelmina?
Billie
Melanie?
Lanie
Henrietta?
Etta.
Abigail?
Abbie
John?
Johnny
Sandeep?