I could debate the above few posts as fairy godmothers and those strange guardians to me are just magical guardian thingies. But if the general public now days associates those things as fairies then at least that clarifies what your thinking.
When I think Fairies I think of my heritage, Ireland, Irish believe. The wee folk. Irish mythology dates back a few thousand years and lists hundreds of variations of fairy folk who all live in their own little dimension or something. I can't expect everyone to know about those references though I guess. (oh, I also think Tinkerbell. But who doesn't)
Certainly, in modern media and depictions what defines a fairy is much more open to interpretation than the history I was looking at and the arguments are fair.
Way this is turning out, the opinion that size is variable is probably fair so I can remove all mention of sizes in the wiki. It does make things a little more complicated for descriptions but I'm sure it will work out.