I cannot be positive if this is what they are referring to but I have an idea.
I had a friend once who was such a strict Adventist that I was really surprised she was my friend. Her family was upset when she married because she decided to wear a wedding ring, that it how strict they were. They did not celebrate birthdays or even Christmas. They saw many holidays as being pagan in orgin so did not celebrate them. I do not think they like Catholics that much either because I remember overhearing her family saying in referance to me once, “At least she is not a Catholic”, I found from my firend that there were two types of Adventists. Traditional and Progressive. My friends Husband was considered to liberal because of the pagan wedding ring thing.
The Historical/traditional still hold to the doctrine that started in the 1800’s and still view Elen White as a Prophet. The more Liberal, I am not even sure if that would be a proper word, but anyway, there are some Progressive Adventist who reject that White was a prophet, either fully or partially, believe there will be other Christians (non-adventists) in the remnant, attend movies, watch tv freely, dance, are not as strict on the sabbath thing, etc…It has caused a huge debate, Conservatives think they are rejecting the very foundations of their faith. It can get ugly, that may be what she was referring to.
