I removed the original text as I realise it's more important to protect my sister's privacy, the issue has been somewhat resolved. I urged her to get professional help as she's clearly got some issues. As to how I found out, my sister left her phone on my coffee table and some very explicit texts popped up on her notification screen. I confronted her and she confessed. The procedure was done and she had a contraceptive device put in. She's going to tell her husband after the holidays.