Specifically that spelling.
I don't know if it is just prevalent in the west country, but I know 2 women at work (2 different workplaces) in the last year who have called their newborn baby daughters Lexxii.
It is (a) a crap name - if you want Lexy or whatever as a nickname fine, but don't saddle a kid with this daft name for life. Call her Alexa or summat and (b) spelling it with tho x's and two i's is utterly hideous and shows the parents as being thick and/or porn fans.