My take on this is that you are the caregiver of the person and I’m sure a caregiver would know if their client has a low IQ. That would make it harder because the person may have a hard time correctly seeing the dangers posed to her by online friends. I have 3 degrees and was a teacher/librarian but am having this same problem judging who to get involved with online and how to handle those relationships, especially with men . I would show her some articles from the internet about social media scammers, womanizers, etc. Ask her if she would ask these people to be her friends in real life and discuss why or why not these people might be a good or bad choice with some possible scenarios of what could happen, good and bad. I made my two best friends online, one a woman I can see in real life and one a man who is across the country. I nonetheless have to give thought and care to how I relate to these friends. I have made some painful mistakes so I applaud you for trying to protect your client.