I've seen a few (4, that I can remember) comments on news articles that I can count from all different people reporting that there was a suspicious male and/or a suspicious vehicle watching the children on the playground play at Isabel's school.
I can't help but think, if this is true, that is is related somehow. I wonder if someone also watched the family, knew the mother left for work each night, and was brazen enough to go in and take Isabel. If she was abducted, whoever abducted her is pretty brave to go into a house, in the middle of the night, and take a child.