Well, we have a baby grand piano. My husband also has a guitar and a clarinet.
My 4 yo daughter has started asking for a guitar, which is nice, but we have the piano and we expect a bit more than her finding middle c before we add instruments.
If we were inclined to add an instrument, it would either be a lyre or a glockenspiel. A guitar is too much, too unwieldy for a 2 year old. Just imo, no judgment. I just think success would be hard to attain or measure. A smaller stringed instrument such as a lyre is very attractive to young children.
Danielle, Nick, Gigi ('08) and William ('11)