Its not something her mother made up. Its a derivative of "
Cynthia", which is a theonym of the Greek moon goddess Cyn.
Other explanations I've seen of the name are "French: Little Cinders".. I'm not sure how they came up to that conclussion, though. 'Cinders' in French is 'cendre', but forming that into a name along with a suffix for 'little' might end up as 'Cendal', but the 'y' certainly chows a derivation from '
Cynthia'.