This is my surname too. Its a bit of a pain to work with isn't it, as so many names run into it and either sound like another word, or just sound daft! When we had dd we decided we wanted at least 2 syllables for first name as we felt all the single syllable names we liked felt a little 'spiky' with such a short surname.
Fwiw our shortlist included
Harriet
Tabitha
Imogen
Nina
Rowan
Beatrix
Xanthe
We went with one of those. We did choose 1 syllable middle name though.
Having said all that if you love Grace then I dont think it sounds bad, and I don't think it sounds too much like 'gracefully'. If you love it go for it I reckon!