She is in jail for exercising her rights under The First Amendment in the U.S. Constitution. While I realize that our country is falling apart at the seems and their is little respect to honor and uphold the Constitution; there are some who still believe it is their duty as American citizens to respect and uphold the Constitution of the United States.
"Congress shall make no law respecting an establishment of religion or prohibiting the free exercise thereof or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
She can practice her religion freely within her family and her faith community, but she cannot impose her personal/religious beliefs on the public at large.
The Constitution is silent on marriage and on homosexuality.
A muslim who kills Jews and Christians in accordance with his religion, is not protected in our system to do so.
What it comes down to is some Americans want evangelical Christianity to be the national religion, and to have it imposed on everybody, Constitution be damned.
It was once the belief of some religious denominations that races shouldn't intermarry. A county clerk in Mississippi during the 1950s would probably have refused to issue a marriage license to a white and black wishing to marry.
But it is now widely agreed that has changed, by both practice and by law. In America religion is not supreme, the civil laws are.