Sitting up on his own

Tyrell has learned to sit up on his own. I wondered how long that would take because he would always throw himself backwards whenever you tried to sit him on the floor. But on Tuesday I was able to leave him alone for quite some time sitting on the floor. He fell over a couple of times and scared himself more than anything but he has now reached another milestone and it probably won't be long until his crawling around getting into everything! Can't wait!?!