Masculine surname

Not Sullivan that’s very boyish for me. The other one wren is good but I think with the field is more boy

I think Renfield could work on a girl as it’s not common for either gender so people won’t have strong associations with it as a boy name.

Don’t use renfield . My son is called Renn and I call him renfield as a joke when he does something weird or gross. Have you read Dracula or seen any of the films? The character renfield is super creepy and gross