Oo, safe naman ang cranberry juice for breastfeeding moms based sa what we know, pero better check with your OB or pedia just to be sure, especially if may specific reason ka for drinking it (like UTI concerns). One of my mum friends drank it regularly while nursing at walang problema, pero everyone's different naman talaga. Pwede ka ring mag-try ng small amount muna to see how baby reacts, though usually fruit juices ay okay lang.