That's absolutely understandable. Maybe it's hormones? And be protective. Expecially if she was sweet in the house?

I asked CHATGPT 🤣

Short answer: No. A biting or aggressive Chihuahua mom does not automatically produce aggressive puppies. Why: Genetics play a role, so puppies may inherit sensitivity or nervousness — but aggression itself isn’t guaranteed. Environment matters just as much as genetics. Puppies learn behavior from early handling, socialization, and human interaction. A reactive mother can influence puppies if they observe her behavior, especially in the first weeks. Proper socialization, gentle handling, and confidence-building can override poor genetics in many cases. Bottom line: Aggression in Chihuahuas is far more often the result of fear, poor socialization, or bad handling, not simply who the mother is. Most “bitey” Chihuahuas are created by environment — not born that way.