Just to give another option, our family is doing a Latin lesson together every day at the breakfast table, using William Linney's Getting Started With Latin. It has no bells or whistles, but it's suitable for all ages and very reasonably priced ($18 for the non-consumable textbook, with free online audio files). Everyone is enjoying the lessons, from DH down to the little ones. Our 4 year old can only answer the very easiest questions, but our 6 year old is doing very well, so I don't think a 9 year old would have trouble catching on.