What should a person do who learns of the prohibition of tattooing after having already gotten one in a hidden place, and what is the ruling on her prayer?

Tattooing is the insertion of a needle or similar instrument into the body until blood flows, then filling the wound with kohl or other substances. It is forbidden, and both the one who does it and the one upon whom it is done are cursed. The tattooed person must remove it and repent. If she fears significant harm, she should suffice with repentance, and her prayers are valid. She must wash the tattooed area if she has not already washed it, due to the possibility of it being defiled by blood.