My point was not that PETA supported breastfeeding based on a study they cited, my point was that PETA, an organization considered by many to be an extremist vegan organization, recommends breastfeeding.
I cannot fathom why I need to explain this to you. PETA hates every human activity that isn’t vegan. PETA does not hate breastfeeding. Ergo, it is reasonable to assume via the transitive property that breastfeeding must be vegan, as it is a human activity that PETA does not hate. The exact same can be said for the vegan society link I provided in a different comment.