An interesting fact about history from my region

So my grandma has tattoos, but not the usual ones (if I told her I want to get one she would freak out). She has one cross on each arm right above her hand, but they are barely visible. She did them with other girls from the village when she was a child (6-7 years old) with coal from the train and needles. Her older sister even has her name on one arm. I asked her how did they even think of doing that and she said most of the elderly women back then had them. Some even had intricate designs on their hands. And there was one with designs on her forehead too. That seemed weird to me because I've never seen any photo of tattooed women from here or learned about this "trend". She said it's probably from the Turks. I'm not sure as I don't know their traditions, I think they also used henna in Turkey like for weddings. But I've also read about some Balkan traditional tattoos that were usually for girls to show they are Christians back when the Ottomans would abduct them. It was both for protection to make them "undesirable" and to remind them of their real ancestry. I'm wondering if they also did that for the same reasons here, especially the crosses.