I just saw this--congratulations!!! I've been wondering when the big B-day would happen! How thrilling for all of you!
My second child, my daughter, would only nap in a sling from around 2 to 4 months of age. We had to be *wearing* the sling (i.e., we couldn't put her down, still inside the sling, or she would wake up). Then right at 4 months she decided that she never wanted to nap in a sling again, and started napping in her crib :). They like to keep you on your toes!!
I'm so happy for you.