One of the things children do in play is experiment with controlling their environments. Play with toy weapons and acting out conflict is part of that exploration. And to a certain degree it’s healthy and natural. If it’s allowed to go too far it can lead to inappropriate uses of violence.
It doesn’t matter if you forbid anything that looks like weapons. A rag doll can become a nuclear missile in a child’s imagination.
A teacher from whom I learned a great deal is the famous Massad Ayoob, one of the foremost trainers of elite law enforcement and military personnel in firearms and defensive tactics. His daughters could have all the squirt guns they wanted as long as they were shaped like animals. And they could whack away at each other with Nerf swords.
Anything that looked like a real weapon was to be treated like a real weapon which meant safety-first, by-the-numbers training. Any time they wanted to do that Mama or Poppa would take some time to give a lesson or practice session. After a certain age they could fire any real firearm in the house which they could safely handle. Again, under supervision. And they had to completely strip and clean it afterwards. The forbidden allure of handling a gun gets old really fast when it means an hour of hard work with patches, bore snakes, toothbrushes, oil and Hoppe’s Number 9.
The Ayoob household is a little different than yours or mine. But the same principle applies. Any toy weapons must be distinctly toys, nothing like real tools. And anything which looks or acts like a real weapon must be treated as if it were one.
And if the really are interested? Well, Lord knows we Jews have to rely on ourselves. If you have a natural Shomer Yisroel, then get him or her proper training. It could save Jewish lives down the road. And that’s a Good Thing(tm).