In my experience living in the U.S., Leigh
as a given name is always "Lee
." I have never come across the idea that Leigh
can be "lee" or "lay" depending on gender. Virtually all of the time, when people use -leigh as an alternative spelling in names, it is intended as just a fancier version of -lee or -ly. So, for instance, I would expect Kimberleigh
to be identical in pronunciation to Kimberly
In Great Britain Leigh may sometimes be pronounced Lay (and the place name/surname Leighton is LAY-tun). Here is an earlier thread about this subject: http://www.behindthename.com/bb/fact/667455 .