What is a mother in her period of breastfeeding called in English?
Based on my guess I looked for "breast-feeder" on Google and indeed I found a documentation of this word in Wiktionary but then I checked it in Cambridge dictionary and is missing there. That's why I'm afraid that there is another word for that term. (I'm not talking about the slang Wiktionary mention there: "boobfeeding" but one that I can be written for example in a presentation or a academical book etc.)
N.b. In my native dictionary I found a "wet nurse", but according to wikipedia it is "a wet nurse is a woman who breast feeds and cares for another's child.". It means that this term is not for the typical woman who breastfeeds her baby.