Leanna

how about a demi-god?

mortal dad happened to hook up with some sea goddess

mom dumped her off with dad at a young age, cause what do goddesses know of child-rearing

the large size came later, but she also has the ability to grant weak "blessings" and is also a sort of lure to those on the water.  Part-lighthouse, part-Siren in a sense

she may have caused some unintentional shipwrecks due to a swim or whatever

I think the design looiks good
fits the aquatic setting
and she isn't a stuffy old god after all
so "regal" isn't necessary