rain-flower-deactivated20160413:

to be honest I don’t really know, there are no clues, the only thing we know so far is that one day Rubens, while fishing, took by mistake this basket (with baby Ruby in it) that was floating near a ship… 

However, theory A: Ruby has been abandoned by his mother, who, since we’re on the themes of pirates, could be one of those women who “work” in taverns (you know what kind of work I mean) because she could not support her.

Theory B: the color of her hair makes me suspect that his real relatives could be magical creatures or something, maybe royals (?)
Imagine if one day we find out that..who know, she is the lost princess of Atlantis or something like that

but this is one of those things in cartoons show that usually could rimain unexplainedunresolved