What is the Army regulation that states a soldier gets 3 meals a day.?

I could use an answer pretty quick. My pregnant fiance is on extra duty. This Sunday they told her that she couldn't go to religious services because she was on extra duty. I showed them that under ar 165-1 they can't prohibit anyone from practicing their religion. However, now they are saying that the time she misses duty because of religious services will be made up for during their dinner. She is pregnant and a meal card holder. I do not believe they can tell someone they have to choose between their religion and eating, especially a pregnant woman.