Okay, the answer is no - the Exp. Share won't get a fair share of a Lucky Egg EXP boost.
When the Lucky Egg is put into the equation, the lead Pokemon gets 75%, whilst the Exp. Share Pokemon only gets 25%. So, it would still get roughly the same.
Hope I helped. :)
Source: www.gamefaqs.com/boards/989552-pokemon-black-version/58519303