Baby talk?

Any tips for dealing with baby talk? It's driving me batty. This DCK is almost four years old but still talks baby talk. Some of it is her speech which seems a bit behind, but some of it is just immaturity I think.

It's driving me bananas. I'm finding it different than whining which is easy to redirect/respond to for some reason.

Thoughts?

I just say use your big girl voice please. And try to remind her a lot that she's a big girl not a baby. If she is asking for something like a drink in a baby voice, say no thank you arent a baby use ur big girl voice and make sure I don't give her the item till she uses her big girl voice. I've had it plenty here. Lucky it was just a phase and with reminding and not getting what they want u till they talk properly it didn't last long. Good luck!

I also point out that Babies say that and you are now a big girl so we say _______
that way you are teaching her the correct way to say it and being the educator as the baby voice and words are okay at home

Had this once too after birth of sibling. I said 'Okay baby, time for mushy food and then time for long nap". If I got argument that they didn't want that I would remind them that's how I take care of babies. Behavior stopped soon after that ;)