My M30 partner F35 wants sex with lights off only all our life.

I'm sorry if this is too private thing to ask. But my partner says she doesn't want to have sex with me with the lights on. She is 5 years older than me. Sex is amazing. However, we've been having sex only with lights off at night for the last 1.5 years. Initially, she said she didn't feel 100% confidence and needed more time. Later, she told me to wait until we got married. Now, as we discussing about marriage she started saying she won't show her body all her life. She always changes her clothes in privacy. Never shower I front of me, never in bathroom changing clothes without door locked. Never sex with bright light, some dim light sometimes, but I'm not allowed to look down. I don't know if this is normal with some ladies. I don't know if this happens with other people. I love her, but I'm worried I might end up having an unsatisfactory sex life, and we might end up having trouble.