It sounds like you are very close, so I would bring up the truth. Just tell her that you saw a discussion on your Catholic forum on tattoos that was talking about what God thought of them and what is in scripture. Repeat the passages and plant the seed. Perhaps she will think on that in future and stop or at least start being curious about God's opinions on things we do in life.
Yeah, I'm giving it careful thought. She does care about God's opinions. She is trying to be a good Catholic. The problem is how she will feel finding out the tattoos she has on her already could be cursed... I guarantee you she will cry when she hears this and be absolutely miserable. I've already planted many seeds about how God probably feels about tattoos, but she doesn't know this stuff I've just learned, about how the ink could be cursed, and evil can be attached to the tattoos themselves.
I totally get this, you have to walk a very fine line. You just never know how someone will react. Wait awhile, the day may come when an opportunity will present itself to discuss this with her.
