How Old Is Too Old To Drink From A Sippy Cup?

That is a question a parent posed to me the other day, and quite frankly, I had never given that question much thought in the past.  I blurted out, "Don't get rid of your sippy cups until you can trust your kid not to make a mess when she drinks from a regular cup."  I think the parent thought she was going to get an answer based on my pediatric knowledge, but the mommy in me answered instead.  Sophia, who is entering first grade, is more than capable of drinking from a regular cup and has been for a few years now, but there is no way I would let her sit on our new couches in the family room while drinking from a regular cup.  Unless she's seated at the kitchen table, Sophia still uses the sippy cup with its ingenious valve because I am too afraid of a mess if her milk or water accidentally spills.  I told the parent that using a sippy cup isn't going to hurt her child's development in any way, so if she needs to continue the sippy cup to protect her furniture and keep her house clean, go right ahead!