Yes, a single M2 will work, you can try 2 closely together or the extra one mounted above the TV(preferred) as this high/low really helps anchor the sound to the center of the TV.

You could also look at using the FMB to mount the M22's to the wall a little higher up to prevent little hands from pulling/touching at them. Once the the kids are old enough(not sure when that is) you can then start playing with better placement or upgrading to floorstanders, this is what I did.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70