I'm very excited and proud to say that Charlie is an official ERFer (extended rear-facer) now! Most people know you can turn a child forward-facing in their car seat once they are both 20 lbs and a year old, but it's actually recommended to keep kids rear-facing until they reach the limits of the seat. This is at the weight limit (most convertible seats go to 35 lbs these days, but check your manual) or when their head is within an inch of the top of the seat. Most kids can safely and comfortably rear face until about age 2, at least.
Charlie is in a Britax Diplomat, which is one of the smaller car seats on the market. As big as she is (and she's pretty big!) she still has 13 more lbs to go and about 3 inches above her head. She will probably reach the height limit first, at which point we will buy a bigger car seat to keep her rear-facing longer. We only bought the little seat because my car is tiny and she has to be at a 45 degree angle which would have been a tight fit. *Hopefully* by the time she outgrows this seat, either I will have a roomier car, or she will have better head control and will be able to sit more upright. If not, I might have to get creative. LOL
A few links:
"Once your child is at least 1 year of age and weighs at least 20 pounds, she can ride forward-facing. However, it is best for her to ride rear-facing to the highest weight or height allowed by the manufacturer of her car safety seat."
And of course, Charlie in her seat:
As you can see, she's perfectly comfortable. Her feet do touch the back seat, but this is safe. I just move them to the side, cross her legs, or bend her knees for her so they fit.