I'm reading Shin Chan and there's a situation I can't quite understand. His mother says they're going to the bank, and Shin Chan starts packing his toy. Then his mother says おもちゃはいいの!!おもちゃは and after that she says something about wondering what Shin Chan understands by 'bank'. Shin Chan runs away and brings back a knife. And his mother says, with a shocked look, where did you learn such a thing about banks?
I don't get why after saying おもちゃはいいの!!Shin Chan runs away to get something else. Isn't she saying that the toy is OK? From the context it seems that Shin Chan understands the toy is not something you would take to a bank.