lactivism

lactivism: lactivismo

Yes, a neologism in both languages, but the Spanish version does actually have some minor googlage.

Here is the wikipedia definition:
Lactivism is a word joining two other words, "lactation" and "activism." A "lactivist" is a generic term describing any person who supports or is in favor of breastfeeding, lactation, pumping, and other related activities which support lactating mothers. Often a person is referred to as a "lactivist" when he/she protests an injustice done against a woman due to her status as a lactating woman. Examples can be found in the current media of instances of lactivism. For example, a common lactivism approach is that of staging a "nurse-in" where nursing mothers congregate outside of a place of business or public building (like a swimming pool) and breastfeed their children to protest against an action that was previously taken against a breastfeeding mother in that place (if she was asked to leave because she was breastfeeding her infant, for example).