Jack lost his expensive earpods now his maid found it and told him that she found it in the living room. But Jack is sure that he hasn't been to the living room in the last few days. After listening to the whole story Jack's brother thinks that the maid intended to steal it but didn't, and says: "She gave it back because she knew that if you didn't/couldn't find it you would've told your father."
1) Is the sentence correct given the context and which conditional is it?
2) Should he have said- "if you hand't found it?"
3) Which one is correct in this context between 'didn't' and 'couldn't?'