Aaralyn started using sippy cups at about 10 months but still had warm milk in a bottle before bed till she was about 15 months. She had a dummy (binky, here) mostly just at night or naps till she was about 2 1/2 (I think) she did not want to give it up and she had a bad cold one time, couldn't breath through her nose but she wanted her binky in her mouth

, so I told her I had to wash it, I secretly snipped the tip off, and told her I accidently broke it when I was washing

she just looked at it, put it in her mouth, took it out, and said I don't like it like that (or somethin like that) she wanted it in her hand at night for about 2 nights then that was it, she was all done with it after that.
I'll be honest it bothers me to see 5 and 6 year old kids out in public with them but otherwise if it's an at home comfort thing, why not?