I want to get a 2nd time mom and her toddler a gift when we go visit. A mom friend suggested a nursing/whiney box for the toddler that gets pulled out only while mom is trying to nurse the new baby.

I think it's a wonderful idea!

If you have something similar what goes in it? If you don't, what do you think would be good items for it?
Her toddler just turned 3 so I'm thinking maybe a coloring book with crayons, stickers, small puzzles?

Any ideas for a cute sign on the box? I'm thinking a big red stop sign with the following note:
Nursing/Whiney Box
Use only during dire circumstances when toddler won't let you nurse baby!!!