Looking at
Ninfia's Bulbapedia page, it has the French name translated as "Nymphali".
The french Eeveelutions all have the suffix of "li", and their prefixes relate to the description of the Pokemon, as in the English names. For example, Vaporeon is "Aquali".
So, the prefix for the French name, is "Nympha", coming from the word "
Nymph".
Which, in mythology, are nature deities, assosciated with certain locations. Which can be places in the sky, or the ground, or the sea, or even in space.
So, it's still very vague in what the actual typing of Ninfia could be. But it gives some reference as to it's design, being that Nymphs are supposed to be beautiful and graceful, hence Ninfia's pink body and flowing scarves/ribbons.