some semi autos can't fire after removal of a magazine...some can.....
None should be stored in a couch, especially in a home where children have free run of the place.
Patently stupid move on Moms part. She should have won a coveted Darwin award had the tots aim been better.
Especially with a round in the pipe. Most couches have wood slats under the cushion. Enough moving and wallowing around could possibly cause a discharge. Not likely, but they don't call them "accidental" for nothing.