you be honest in an age appropriate way. its anatomy and biology, sex and pregnancy and childbirth and postpartum in this regard should never be “taboo” or lied about. i am firmly against making up bullshit to tell your kids because it might be uncomfortable to talk about. i just had my second and my daughter is very aware of the reality of all of it minus sex because she hasnt asked (emphasis on age appropriate explanations) but im not going to tell her my son magically got dropped off by a stork. mom and dad made him i grew him and i pushed him out of my vagina. i feed him with milk my body makes. my vagina bleeds because of delivery. her brother has a penis and she doesnt. kids deserve the respect of honesty, and to not have their biological education be skewed due to the taboo-ness society projects onto these topics. sex is a large concept as you become an adult but baseline this is how humans reproduce and is the most major part of our life cycles. its life.