I have read (from reputable sources) that lavender can mimic estrogen, and should not be used on children (or adults who have had certain estrogen-related cancers) in the form of soaps, lotions, and especially oils.
It was apparently discovered when a number of pre-adolescent boys were developing breasts. (Tea-tree oil was also implicated, but probably in a different study).
I know that many people are not aware of this, so I think that a warning or mention on lavender-containing products would be helpful.