My bulldog ate her puppy. - Page 2

Eating a puppy does not necessarily mean that she is dangerous to your son. As others have said, sometimes a mother will do that if something is wrong with the puppy that you cannot see yourself.
A bitch may also do this if she is stressed out, possibly by you and/or your son not giving her privacy (I don't know this, just offering suggestions)
Other dogs "just do it" and there is really no good explaination for this, but the particular dog should not be bred again IF she were to eat the whole litter or several of them. That's my opinion.

A couple of examples. I had a bitch kill and eat an entire litter and they were two weeks old. This bitch was extremely high strung. I have no explaination as to why she did this, except that she wasn't right in the head and so she was never bred again. She was excellent with people. She did this all within one hour so there was nothing I could do by the time I went to check on her again. She had already killed them all.

A family member had a doberman who delivered 13 puppies. Every day she ate a puppy until there was only one left. I was very young when this happened, so couldn't offer any suggestions or advice, but looking back they should have been taken from the mother and bottle-fed after seeing what the mother was doing. Another bitch that was never bred again.

Muzzling the bitch will just stress her out, and I don't recommend muzzling buldogs for any length of time anyway (I am assuming it's an English Bulldog)
Anyway good luck. Keep the mom in a quiet spot  and try not to bother her too often, also handle the puppies as little as possible. If she continues eating the puppies, take them away from her and hand feed them.
Stacy