Hum?! Can you be a little more explicit on this explanation? With my Latin, I can recognise the "wing", but not the "light" part (that would be levis, most naturally). Also, what do you mean with "early Britain"?
Did you make it up yourself, or did you get from another source (which?)?
P.S. Pretty all we currently know about the name Alafair is summarised in this submission:
http://www.behindthename.com/submit/name/alafareThis message was edited 7/3/2014, 1:30 AM