I think it could be highly relevant to her possible state of mind and if the investigation were to lead to a scenario in which she could have driven to SNP with the intent to harm herself it's definitely relevant. (Not saying that's what I think happened but if that does turn out to be the case it will certainly be relevant to investigators). The comment with her full name, on the Internet, where anyone could see it or find it could definitely cause severe emotional distress, and no one but her knows how well she handled it or "weathered the storm." Likewise, if she is separated there's no specific guidelines for how a separation effects every person. Nicole was aware of the comments, and I think it would be a mistake to write it off as irrelevant to her being missing.
If Nicole is the victim of foul play, investigators would also factor this into their victomology which helps them determine possible motives, suspects, or risk factors and by risk factors I mean life style, occupation, or anything else going on in her life that could point to a motive or suspect.
With that being said, the comment from four months ago, or her current marital status may end up having nothing to do with this case but it still would be looked into and noted by investigators.