My kids are close in age and from very early on I was able to get them on a similar napping schedule. For my own sanity I knew I needed a nice break in the middle of the day, and thankfully my children cooperated with my insistence of napping at the same time. I looked forward to their shared nap every single day. It was pure bliss having that one or two hours (and sometimes three!) to clean up, fold laundry, write blogs, watch TV and sometimes even take a nap myself. But my son started K4 preschool and they no longer put him to nap during the day, which means he no longer wants to nap at home either.
I fought it at first. But every time I would try to make him nap with his sister he would cry and refuse. I had to face it—nap time for my boy was over. I would still really like that mid-day break though, so I have to find ways to keep him busy—and quiet—while his sister naps. Here are a few things that have worked for us:
Coloring/Painting. My son could sit and color forever. He loves drawing and mixing colors and is always so proud of his creations. For that reason I keep art supplies fully stocked. Crayons, markers, finger paints, watercolors, chalk—we have it all and he's free to use it all, as long as he works quietly.
Reading. We also have a bookcase full of books for my son to look through. I try to encourage him to "read" on his own or I buy books that are interactive for little ones. Open-the-flap books or books with a musical component. This can keep him busy for a while as well.
Writing Practice. He's learning to write letters and numbers at school so I will sit him down with a workbook or handwriting paper and have him practice writing. He actually really loves it!
Puzzles. This boy has loved puzzles since he was a year old. We have quite a few different ones that he can work on while sister sleeps.
Play-Doh. For a long time I didn't want Play-Doh in the house because it's so messy, but who am I kidding? Life with kids is messy, and that's okay. So now we have Play-Doh and it's a quiet time favorite as long as it's kept to one small area of the house to contain the mess.
iPad Time. The kids have an iPad filled with games and movies. If all else fails, he can sit with the iPad for a while to watch some shows or play some games. It keeps him occupied and I can even sit right next to him on my computer getting work done.