Re: sippy cup
My guy is 6 months, and he managed to use a straw at 5 months. It was actually a mistake; I let him chew on my smoothie straw, and he ended up sucking in smoothie. It really made him angry.
I swore I wouldn't use a sippy cup, but the cheapo disposable ones are really easy for my son to maneuver. Not too much leakage if they tip, even though they don't have a valve.
Johann, Born June 21, 2009 8lb, 7oz & 22in nursed until 2 years old
Lydia, Born March 30, 2013 9lb, 5.6oz & 21.75 inches
Nursed through hypothryroidism, IGT, and a SNS both times around