It doesn't only affect her and her baby. It has public health implications so it also affects tax-payers.
Sorry don't buy it. As far as I am aware, Although there are studies showing 'links' to various health concerns. There has been no causal effecfts actually proven. Unless you can show me in hard cold $ where formula feeding babies directly causes or contributes to an increased cost to the tax payer, This argument is week at best.