Pradeep C (author of Thanjavur - cultural history) shared some nice highlights about Tiruppavai + Andal on itsdiff weekly tamizh radio show hosted by me on stanford radio.
Very interestingly he shares the period of existence / Date Andal lived - and research scholars indicate, that 1 and 13th paasuram kind of indicates that. He also shared the food items like pongal, akkaravadisil, sakkarapongal etc.,