R.Y.
I went to one afternoon nap with my twin girls when they were about 14 or 15 months. They started taking one longer nap and one shorter nap. They usually get up about 6 or 6:30, play hard, go outside, etc, have a snack about 9:30, lunch at 11:30, and then nap after lunch (usually 12-3). Bedtime is by 8pm, but if they've had a really busy day, I just put them down about 7:15 or so. Also, my girls still sleep together at night, but I have started separating them at nap time and have found that to be conducive to longer naps. Hope this helps!