With Tillie a new favorite of avant-garde parents, the British music-hall Tessie might conceivably follow. 

Tessie

A favorite in England and Wales where nicknames as given names are very much the norm, Tilly has the potential to catch on in the US, given its similarity to the popular Lily and Ellie and the rising stars Millie, Billie, Kallie, and Nellie. 
 
Most often used as a nickname for the strong but lively Matilda, Tilly might also work for recently popular Ottilie. Other less obvious possibilities could be Chantilly, Talitha, Natalie, or Talia.
 
As a stand alone name, Tilly is cutesy but not flimsy, and in recent years, it has been racing up the US charts. Nearly doubling in usage since 2018, a recent count revealed Tilly is given to nearly 250 babies each year. When you combine this with the number of Tillies too, the figure is more like 400. 
 
Notable Tillys include Tilly Ramsay, daughter of Gordan Ramsay, and a chef, present and influencer in her own right; Tilly Keeper, an actress in British soap Eastenders; and Tilly Edinger, a German-American paleontologist who founded paleoneurology.

Tilly

This pet form of such names as Winifred and Edwina and Gwendolyn has loads of vintage charm, a la Millie and Maisie, with a decidedly winning vibe. And it just got celebrity cred as the baby daughter of Jimmy Fallon.
 Winnie had been used regularly on its own in the U.S. through the early 1950's and has a number of varied namesakes. There's the Pooh, of course, and also Winnie Mandela, former wife of South African President Nelson; Winnie Cooper, the charming girlfriend of the young hero on The Wonder Years--whose given name was Gwendolyn; Winifred "Winnie" Foster, a main character in the childhood classic Tuck Everlasting; and it was also a nickname for Winston Churchill.

Winnie

relizabeth's list "Cutesy Names" of 3 great name ideas: Tessie - Winnie!

Cutesy Names

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