You're not overthinking a thing!! This is one of the many, many, many reasons I often steer clear of social media due to people feeling obliged to posting something without thinking first, particularly when it has nothing to do with them. Your daughter was celebrating these friendly, adorable exchanges between you and herself and her stepmom made a comment.

I'm not sure what your relationship is like with your daughters stepmom but I would suggest you not give this any thought at all as difficult as it can often be to ignore things like this.

It's a subtle, innocent, beautiful photo and she unfortunately doesn't seem to appreciate it. What's important is that your daughter loved it