The real question is why is her 9-year-old son pulling a knife on kids?

Defending yourself is one thing, but pulling out a knife is a different story. This mother had every right to pull up and ask these kids who stole her sons knife, but really should a little kid have a knife to begin with? Plus all the stories from the kids saying her son pulled a knife on them match up, so who really is at fault here?

If someone pulled a knife on me I'd do everything I could to take the knife away before someone gets seriously hurt.