I like the idea of [name_u]Kit[/name_u]! The obvious full name would be [name_f]Catherine[/name_f]/[name_f]Katherine[/name_f], which would work because it’s a classic name that fits in every time period. However, I’m guessing you’ve already though of [name_f]Katherine[/name_f] so other potential ideas could be [name_f]Katerina[/name_f], [name_f]Kirsten[/name_f], [name_f]Christine[/name_f]/[name_f]Christina[/name_f], or [name_f]Kathleen[/name_f]. Or, the American girl doll [name_u]Kit[/name_u]’s full name is [name_f]Margaret[/name_f] [name_f]Mildred[/name_f] Kittredge, [name_u]Kit[/name_u] coming from her surname so you could go that route.
For the love interest, I looked at the most popular names of the 1750s and thought of as many nicknames as I could for them. Not sure when these started being used, but if you find one you like, maybe you can find that out!
[name_m]John[/name_m]- [name_m]Jack[/name_m], [name_m]Johnny[/name_m], [name_m]Joe[/name_m], [name_u]Joey[/name_u], [name_u]Jay[/name_u], or initials, such as JT or [name_m]JR[/name_m]
[name_m]William[/name_m]- [name_m]Liam[/name_m], [name_m]Will[/name_m], [name_m]Bill[/name_m], [name_u]Billy[/name_u], [name_m]Willy[/name_m], [name_m]Wiley[/name_m], or [name_u]Lee[/name_u]
[name_m]Thomas[/name_m]- [name_m]Tom[/name_m], [name_m]Tommy[/name_m], or TJ
[name_m]Richard[/name_m]- [name_m]Rich[/name_m], [name_m]Rick[/name_m], [name_u]Ricky[/name_u], [name_m]Dick[/name_m], [name_m]Richie[/name_m], or initials like RJ
[name_u]James[/name_u]- [name_m]Jim[/name_m], [name_m]Jimmy[/name_m], [name_u]Jamie[/name_u], [name_u]Jay[/name_u], [name_m]Jase[/name_m], or initials
[name_m]Robert[/name_m]- [name_m]Rob[/name_m], [name_u]Robby[/name_u], [name_m]Bob[/name_m], [name_u]Bobby[/name_u], [name_u]Bert[/name_u], [name_u]Bertie[/name_u], or initials
[name_m]Joseph[/name_m]- [name_m]Joe[/name_m], [name_u]Joey[/name_u], [name_u]Jay[/name_u], [name_f]Josy[/name_f], or initials
[name_m]Edward[/name_m]- [name_m]Ed[/name_m], [name_m]Eddie[/name_m], Ted, [name_u]Teddy[/name_u], [name_m]Ward[/name_m], or [name_m]Warden[/name_m]
[name_m]Henry[/name_m]- [name_m]Hal[/name_m], [name_m]Hank[/name_m], [name_m]Harry[/name_m], [name_m]Hayes[/name_m], or [name_m]Hale[/name_m]
[name_m]George[/name_m]- [name_u]Georgie[/name_u], and that’s all I got
[name_m]Benjamin[/name_m]- [name_m]Ben[/name_m], [name_m]Benny[/name_m], [name_m]Benji[/name_m], [name_u]Jay[/name_u], or initials
Here’s the full list, girl names included if you want more ideas for MC or MC’s sister: Gorgeously Georgian - British Baby Names
MC sister:
[name_f]Agnes[/name_f]
[name_f]Augusta[/name_f]
[name_f]Dinah[/name_f]
[name_f]Dorothea[/name_f]
[name_f]Dorothy[/name_f]
[name_f]Euphemia[/name_f]
[name_f]Fanny[/name_f]
[name_f]Georgiana[/name_f]
[name_f]Henrietta[/name_f]
[name_u]Joan[/name_u]
[name_f]Margery[/name_f]
[name_f]Theodosia[/name_f]