Today Iona and I travelled on a coach-like bus to a neighbouring city for a home ed event. Having settled into our seats Iona looked up at the units above and said "Why is that "stop"?". I looked where she was pointing and found she was showing me the "STOP" button above the seats. She had never sat in a similar bus, with similar buzzers, so she had not recognised it from context or (I think) font. I therefore think it's safe to say, that Iona read her first word independently today - WOOHOO!!!!