I find
Luc on a girl totally weird and... no.
Luc (prn. not look, but with a French "u") is a common name in my country, and totally male.
Lucy pron. looky seems totally weird and ugly to me, although I love the normal
Lucy.
I love the other names, but not with a hard c, except
Luciana (loo-kya-na in Latin, so ok). Sorry.
What about:
Luca,
Lucasta,
Lucia (Latin prn, loo-kya),
Lucija (loo-ki-ya),
Lucilla (loo-ki-la),
Lucretia,
Lucrezia,
Luksa (loo-ksa)?