For one, she has started sitting up much more easily than before. She still falls over on occasion, but she's capable of sitting there for many minutes at a time, playing with toys or just watching the world. She still isn't crawling, but she has flipped herself over a few times. She really loves music. She has a xylophone that she beats on all the time, and whenever you sing to her, she joins in (well, as close to harmonizing as she can do at this age, anyway!).
Her vocabulary continues to improve. I swear she is now saying several words. Her grandfather visited recently, and would say 'OK, OK, OK' to calm her down. Well, now Alex is saying that, and quite often, with the same intonation and everything! We have also heard her say 'cat' and, honest to goodness, 'I love daddy'. One time she said that and it was so clear that it nearly knocked me off my chair. Now, whether she understands what she's saying is another matter...
She has two prominent teeth on her lower jaw, and several more starting to erupt in other parts of her mouth. She has also started to eat food for the first time. Just a couple of weeks ago we gave her her first meal, some rice cereal. Later we tried sweet potatoes and pear sauce. Weirdly, she seems to really like eating this stuff, and asks for more, but when we put it in her mouth, she always makes a really sour face. Every time! But then seconds after she swallows, she reaches out to the spoon to get the next helping.
She's starting to really like sitting in her high chair while we eat. As long as the tray is on it, with plenty of toys to distract her, she's happy. Of course, those toys end up on the ground pretty quickly, but mommy or daddy are there to make sure she gets them back quickly. I can't wait to see what her next new tricks will be!