Toddler milk sippy cup through TSA?

We had a clear 16oz sippy cup of whole milk for my DD ( 2.5 yrs old) to drink during flight. A TSA agent said that she would make an exception this time, but milk would have to be discard at TSA next time. The TSA agent said that they expect 2-year-olds to take airport food after the TSA check points. Is there a written policy that milk can’t be brought through TSA and the age limit?Of course I don’t mind dumping out the milk, and get milk refills at Starbucks or something after TSA. But that costs money and time to get in line. I don’t mind opening the cup for them to check the milk at TSA. But I understand that empty cups would speed up the TSA process a bit. via /r/Parenting https://ift.tt/2ZE1tRc