Jennifer now is married and has three children of her own.
now是个副词,位置是灵活的,可放句首,句中(动词前、动词后),以及句末。
英语中很多副词都是位置灵活的,比如:
Quietly he leaves the room.
He quietly leaves the room.
He leaves the room quietly.
应该是 ... is now married ...