Probably you are just discovering that lots of parents in the world besides your mother create new names.
Caribbean and Filipino cultures are both ones where newly created names are fairly common. One way parents commonly invent new names is by blending sounds from two other names. Genneille is something that many people could come up with by combining the start of
Jenny or
Genevieve with the ending of names like
Camille,
Lucille,
Corneille,
Mireille, etc. So it's probably been "reinvented" by separate parents several times.