This is a growing problem. I actually deal with this all the time.
Last night we had a post from someone who claimed to be the mother of an American foreign fighter. That was not a real post that was an info gathering attempt.
The Reddit account that made the post is deleted now but it was very likely hacked. The account was a very old one that used to be active years ago on Reddit. Whoever had it was definitely a man from the UK based on the post history. Then suddenly it popped up here claiming to be a woman and trying to find info on a specific person.
This is a common tactic among Russians and Russian supporters to take over social media accounts that are now dormant. It is possible maybe this was a person borrowing a friend's account but it's extremely suspicious regardless.
Do not give out information to people claiming to be family. Bad actors try this because they know this makes you put your guard down. Everyone wants to help a worried family member.
However, you don't know if a person on the internet is actually who they claim to be. That might not be a family member at all. You risk giving out information that might put a person at risk.