At 19-months, RPGBaby surprised us by counting from 1 to 5, unprompted and correctly. The very next day she made it to 6. She has continued to increase her range, but she always leaves off 7. At first I thought it was because it was a two-syllable word, but now that she can count to 11, I have to form a new hypothesis. My current one is that her current rules are based on a D6 system and that we need to get her on an open-source D20 system quickly. Then we can upgrade her to percentiles.