thomasina...

[herhonesty]

Thomasina
Jemima
Martha
Scarlett

Oh wise mumsnetters.........

Martha definitely gets my vote eg Martha Kearney on BBC Radio 4.

Thomasina is next best, although the names of the Lawson sisters Thomasina, Nigella and Horatia show it in dubious company. I have never heard it used, only ever heard of the character Thomasin Yeobright in Thomas Hardy's book 'The Return of the Native' which shows how it became Tamzin/Tamsin I suppose.

Jemima is a puddleduck and a bit too little girly for my taste.
Scarlett starts with 'scar' and is too of the moment.

I like Thomasina the best

Otherwise:
Martha - lovely name, but there do seem to be quite a few small ones around if you're looking for a less usual name (wouldn't bother me)
Jemima - fine, but I have only known very very posh ones, which 'places' it too much for my taste
Scarlett - OK, but somehow wouldn't suit a mousy quiet child IMO, so depends on personality. Also, not sure how it could be shortened, if you would want a shortening.

There's a Thomazine in this book - trash historical romance, but the author has a good line in names