What's your opinion on moringa olfeira? I've heard it's great to boost supply and nutritional value of mothers milk but I also read that women of child-bearing age shouldn't take it?

Not well-studied. It is great for mother to provide breast milk to their infants. There are many health benefits for both involved. However, I do not recommend substances like moringa olfeira because of the lack of data. Does it help, i'm skeptical; could it harm either the baby or mom, not worth the risk. Disclaimer: I am a physician-scientist who likes data.
Never tested. It's widely used as food and folk medicine in many places in the world, but it has never been systematically tested for safety. The "boost supply and nutritional value" experience comes from mothers whose own nutrition was inadequate until supplemented with moringa; there is no evidence it will do the same for otherwise well-fed women.