Oh, I just noticed this was the June thread... but I didn't reply in June and it's up here at the top of the forum again so anyway...
DS (21 months) finally came had a vocabulary explosion and started making phrases... thank goodness! His sister was such a talker that I feel like we've been waiting foreeeever for DS to really talk. He's hard to understand but it seems like half of what he says relates to shapes or letters. He probably knows as much of the alphabet as DD did at this age, which continues to surprise me because he's never seemed as interested in intellectual pursuits as she was--he'd much rather sneak into the bathroom and make a big wet mess on the sink than play with letter magnets. He's an excellent problem solver and can now reach just about anything in the house, turn anything on or off, and has just learned to open the baby gate at the top of the stairs. He may well turn out to be a supergenius but only if he doesn't manage to kill himself first.
DD is hard to define lately. Her reading level is high enough that I'm not really sure how high it is. We recently picked up nearly all of the American Girl books at a book sale and have been reading them together (I stashed them in the top of her closet where she cant' get to them or she'd've read them all to herself by now, but I'm tired of her reading ahead whenever we are reading a book together!!).
I'm working to enroll in a master's in teaching program in the fall and have been studying up for a pre-admissions test by brushing up on things like algebra, biology, physics, etc. DD has been making off with my study materials (YA/J-level books from the local library). She's spent the entire last week talking about molecules, vacuums, and chemical reactions. Like this morning she had a cup with a straw in the car and was making vacuums with her straw and talking about how the walls kept the air molecules from getting in, and stuff of that nature.
I also recently picked up a lovely teaching manual called "Literacy: Helping Children Construct Meaning" and having been working with her on increasing her reading comprehension though intentional literacy activities like story prediction and summarizing what we've read.