This is a silly question. You shouldn't have told your mom. It's too late now. The lawn-keeper? The lawn-keeper probably doesn't care enough to repeat the news to others (unless the secret is that you won 50 million dollars at the lottery). It's your mom you have to worry about. The only way you can turn this around is to say that the secret was a mistake, or that the secret didn't go as planned. In other words, the only you can stop your mom now is to lie to her about the secret no longer being true anymore. —
Stephan Branczyk 55 secs ago