I have a friend who swears by putting on lavender diffuser and some lavender oil on her 8-month olds feet to help him sleep. Is it advisable to use a lavender oil on babies so young?

I have read that lavender oil is safe for babies older than three months old. I found this article very useful in learning about using essential oil on babies: http://www.thehippyhomemaker.com/essential-oil-safety-babies-children/ In general, according to the article, it is best not to use any essential oils on babies under three months, and to always dilute the oil before using it. The article listed the different oils that are suitable for babies of different ages.