Headcanon that Baby Michael’s middle name is Emily.
This is because in those 6 hours after ‘200′ before she returned to London, Emily and Will (who have been drinking buddies for years) got absolutely shitfaced drunk. About five hours and a very large amount of alcohol later, Will promised her that if he and JJ ever had another baby,because Emily now had risked so much to save both of their lives; (defusing the bomb he was attached to in ‘Run’ and of course, saving JJ), then boy or girl; it would be named after her.
Therefore when Emily found out that JJ was pregnant, she made sure that Will followed through on his promise to ensure that when the baby was born, he would be named Michael Emily LaMontagne. JJ wasn’t exactly happy with Will’s choice of a middle name but she supposed… a promise was a promise.