After a bit over a week, our other two started today as well. Black Betty (the black and gold Polish) laid her first ever, I think. She is a bit smaller so I peg her at only a few months old. She was sure walking around squealing funny, then jumped talons first at my wife who was cleaning the next box this morning. Once that was done and she got her privacy back, she went up there and laid us a little white egg. Betty Red (the Rhode Island Red) must want in on the fun, as she went up and laid a large brown egg about an hour later; she wasn't laying when we got her as she just "weaned" (?) a recent flock of chicks and hadn't started back up yet.
With all three going (Betty White - a white Leghorn as best as I can tell - has been laying most every day since day 1), we should be about a dozen and a half a week. That's not bad for our family of 4.