heuerfan,
Do you have pictures of the male? Is it a juvenile?
The female can be larger than the male but typically that is not the case unless the male is a much younger specimen like a juvenile. They still should get along.
One thing to watch out for is that in fairy wrasses, many other species of fairy have females that look like this. Also in other fairy species, when the fish is very young, it has a pink body with a black dot at the start of the tail.
Just want to make sure you do have a true pylei. Your picture is a liittle off but it appears to be a female pylei