Just a guess, but I think Tikeya has you trained. It's fun for a dog to go check things out in the middle of the night. She knows that you will get up and let her out and back in when she so desires. She knows that your mom won't! She's just figured out who the softer touch is!

If demands to go out for a pee in the middle of the night, take her on leash to a designated area. Give her a couple minutes to do her business and take her back in. She'll soon figure out that it isn't much fun anymore and stop asking.