I have made Abby laugh many times now. It's delightful. Sometimes with tickles, sometimes with a toy, sometimes by making a weird sound, sometimes by just breathing near her--you never know what will set her off. However, each attempt results in exactly one laugh. That is, she'll giggle cutely for a moment and then, when you attempt the same stimulus again, she will look solemnly at you, as if to say, "Mother,
do stop that ridiculous activity. It is most unbecoming."