Why did my ex's sister in law unfollowed me on Instagram?

My ex an I broke up in March, but nobody knew until April. In April, I remember I messaged her on Facebook for advice, since she went through an on and off relationship with my ex's brother for many years and I wanted to know her opinion about my situation with my now ex. I thought she would sympathize with me and give me some perspective, especially since she went through breakups (I'm not in that kind of circle since everyone around me has always been continuously happy with only minor discussions here and there)... but she just left my message in read and never replied. I remember I felt bad because if it was me, I would have seen a woman that was clearly heartbroken looking for answers...

Anyways, I deleted her and her husband on Facebook and unfollowed them on Instagram a few weeks ago. I was debating whether or not to delete the aunts and cousins but I figured to keep them since they were not really "involved" in the breakup.

Anyways... today I found out she unfollowed me on Instagram... which is ok I guess, but I also find weird. I mean, I remember when my bff's 1st husband was heartbroken about my friend cheating on him and leaving, he deleted and blocked everyone he met through her on social media, and the only reason I don't follow him anymore is because he blocked me. But if he had only deleted me, I would have understood why he did that, but I would have not unfollowed him.