I did a search as well to try and help you out.. Found basically the same thing. The only thing it came back with was "unknown if safe in quantity".
Although most sites I saw said to limit it to a maximum of 2 cups daily. I did see other herbal teas and breastfeeding and it said pretty much the same thing, in small quantities it did no harm..
Heck even saw she can have a beer!

(not a 24 pack of course, just one!)
I often wonder if I worry too much myself.. Our baby is only 9 days old today, but I imagine that after a month I'll still be worrying and won't stop until she's off and has her own kids lol.. Or maybe even then...