Wedding after secretly married for three years

I need some advice.
My best friend, who has been my best friend since school, has given me information that has let me flabbergasted and I'm honestly not sure how to proceed. I'll do my best to summarize. Early January this year she called me and sent me pictures of her ring, telling me that her boyfriend had proposed. I was thrilled for her. The next months have been filled with wedding planning for September, her asking me to be a bridesmaid, etc. Well about two weeks ago she told me that they have actually been married for three years. Apparently she was being removed from her parents' insurance and they married to get her on his insurance (he's military.) She never changed her last name or told anyone. The only other people that know are each of their parents (and they were told well after the fact as well.) I initially told her that I was a little hurt that she hadn't told me for three years but that was about as far as it went. The more I have thought about it the more upset and bothered I have become. Not because she didn't tell me for three years, I could get past that. But the fact that all of this is a LIE. She is planning and has her parents paying for an elaborate and expensive "wedding". The location for the ceremony alone is thousands of dollars. She has a registry; or as she said a month ago a "chance to get new stuff." None of the guests know, even one of the other bridesmaids doesn't know. I'm not attempting to shame her for getting married before, I would have been happy for her then. Getting married primarily for insurance is not my preference but to each their own. And if this was just a celebration I could understand. But no, it is all a sham. She is pretending to get married to her husband of three years, expects gifts, is having the charade of a lifetime and it's all a big secret. I have barely talked to her since she told me because I don't know what to say. I don't want to be ugly to her, but I am truly bothered. I am very uncomfortable with dishonesty and with this entire ordeal. I'm to order and pay for my bridesmaid dress and whatnot. I understand; that is standard. Texting me about her stress of wedding planning, all the pictures of what veil to wear, picking out the caterer...I just can't. How she convinced her parents to pay for it is beyond me. She said they didn't take the news of the secret marriage well initially. Am I wrong for feeling mislead and uncomfortable (and a bit upset) with the whole situation? I don't want to be a bridesmaid anymore. I feel like this is a big case of wanting to have your cake and eat it too.
Thank you all in advance!