I don't follow the rule of flash card.
Everyday, I just read one time of "15" 字/詞語 to her, I prefer to use the "verb", so that when I read the word, I will do the action. She find it funny with action.
In addition, I will print the whole child song on first page, and follow with the "words" in the song, but max "10"字/詞語 for each song. 既然可以唱歌學英文, 當然有唱歌學中文.