When girls are between eight and 11 years old, the two ovaries in their body begin to grow bigger. Each ovary is egg-shaped, and is attached to the side wall of the pelvis. The pelvis is a large set of bones in the hips. The ovaries are organs that make female hormones. These hormones cause a girl to grow into a woman, and make her feel like a woman. The hormones also make it possible for females to become pregnant and have babies. Inside the ovaries are about 200,000 ova (egg cells). For a baby to be formed, a woman's ovum and a man's sperm must come together. During puberty, the ova also grow bigger.