I can't get no R-E-S-P-E-C-T!

Me: "Hailey, it's time for bed...so I need you to go potty, get your jammies on, put your shirt in the wash, tell Dada to come upstairs, and then get 2 orange medicines off the..."
Hailey: "Blah, blah, blah, blah..."
Me stopping dead sentence: "...?? Hailey, did you just say blah, blah, blah to me?"
Hailey laughing and smiling: "Yes!"
Me dumbfounded, but laughing: "Ok, that was pretty funny, but don't do it again because it's rude. Where did you learn that anwyay?"
Hailey still laughing: "I just made it up. When you talk to me I think in my brain 'blah, blah, blah!'"
Me still dumbfounded, but cracking up while my sister is rolling in her chair laughing her head off: "Oh, that's nice. Don't say that anymore, ok?"
Hailey STILL laughing at me: "Ok Mom!" And she walks away.

Seriously....!? She's not even 5 yet. Is it too late to give her back, cuz I don't want what's coming to me in the years to follow!