My almost 8 month old DD yawns after long naps. She seems alert and refreshed but worrying about excessive yawning if not sleepy. For examole, she has woken up from a two hour nap today and yawned 3 times in theast half hour since waking up. She sleeps from around 7pm to 7am maybe waking up briefly once at about 4am. She naps throughout the day. I've read in a few places online that this could be a sign that something is wrong. Has anyone else experienced this?