well that would depend on if you want a 'sounds-like'
Thomasina name or the same meaning of
Thomasina. The meaning of
Thomasina being 'twin' is telling me that it's highly probable that it will be somewhat hard to find a same-ish meaning in chinese. These's none on this site with meaning of 'twin' and I can't see the Chinese people celebrating twins when they it's one child population, preferably boy.