Try putting Meeko in a small room, of his/ her own, for a while, until she knows that the litter box is the potty spot. Slowly give the kitty the run of the house, room by room. It is what we did with our dog, He still doesn't have the privilege of the bedrooms or kitchen, but he has the rest of the house. After he is a full year, and we KNOW he is fully house broken, he will get those other rooms.
Another thing to do, is when you see Meeko not using the litter box, pick her up immediatly and put her in her box to finish up. It worked with the one litter we had when I was a kid.
But most of all, you have to be patient. It is just like potty training a child. They don't get it at first, but after a while, they understand what the right thing to do is.
"Every beginning is some other beginning's end" Closing Time- Semisonic