I also posted this in the bottle feeding section.
My DD is nearly six months old. For the last few weeks she has been drinking water from an Avent Magic Cup with a teat. Today I tried to introduce the 6 month soft spout. She found it so hard to suck the water out that she got frustrated and I put the teat back in.
How did you introduce a sippy cup? What age was your baby? What sippy cup did you use? How long did it take for your baby to adjust to a sippy cup? Did you find that the valve made it harder for your baby to use?