When I asked my mom how babies were made (around age four or five) she told me that when a husband and wife want a baby, seeds from the daddy's body goes into the mommy's tummy, and swim to the egg. The egg and the seed go together to make a baby, and God made the baby grow.
That satisfied me for years. In my little girl's mind, I just assumed that the mommy and daddy hugged each other hard, and the seeds magically crossed through the belly button, or something. I was happy that I knew, and didn't ask anymore questions until I was much older (around age nine-and-a-half, I think).
At that point, I was given the basics of how things worked, and encouraged to ask questions if I had any; and every time I did have a question, my Mom was more than ready (if a little uncomfortable or nervous, still I could see her bravely stepping forward, and that encouraged me) to answer my questions and talk with me, so I always felt able to talk openly with her about it, which was SUCH a bonus and relief.
I hope this helps! God bless!
M. D