My DD2 is the same age as Heaven's DD1 and she speaks in 12 word sentences, can sing entire songs (including ABC, Do-a-deer and Spoonful of Sugar) and can have an entire conversation with people. She also memorises books after 1 or 2 readings. I have put this down to her wanting to be like her sister and really pushing herself to be understood.
She's gorgeous hun and very smart i assumed she was closer to A's age when they were catching up together