Is it true that even adult women have vaginas?

I've been saving myself for marriage, so I've never had sex with a girl. I've never even seen a girl naked. Anyway, I finally got married a week ago to my beautiful wife, Christine. She's perfect in every way, except she has a vagina. After seeing it, I'm too afraid to...you know...get intimate with her. I've always known little girls have vaginas, but I always thought that they turned into penises when they reached puberty. She says this is normal, but I don't know. I was homeschooled, and my parent's didn't teach me sex-ed, so I don't know if this is true.