It's normal for bearded dragons to shed in patches, unlike snakes. If you think about it, that figures, since they can't pull it all off in one piece like a stocking the way a snake can because they have arms and legs and fingers and toes, not to mention all those little spikey scales, which tend to be a sticking place.
(My first reptile was a snake so I had to get used to not thinking something was wrong when the beardie's sheds didn't all come off in one piece.)
It sound like Maggie is doing well -- lots of growing is what she's supposed to be doing, and the shedding goes with it when she outgrows her skin (including the "shrek boogers")