Question about focusing on multiple faces in portraits.

Just looking for some advice on getting good focus on muliple subjects while shooting portraits. My problem is coming in especially when I have small children sitting forward on parents laps and they don't keep completely still. Any suggestions?

The accepted way of doing this is to choose a reasonable aperture to help maximise the depth of field (f/8-f/12 or so), and try to pose the family so that their faces are of a similar distance to the lens. So if the kids are on the parents laps, have them hold the kids a bit to the chest and get the parents to lean forward a little.

Or change your angle so you're shooting slightly from above (thereby tilting the plane of focus).