She still stalks me...

I've been with my husband for over two years. In the beginning of our relationship, his ex girlfriend was very slanderous of both my husband and I but we just ignored it because we don't have time for it. She called him a loser with a bad job, broke fuck, I was "temporary" and blah blah. Whatever.
Well, I had totally forgotten about her until 10 minutes go when one of my Instagram photos got liked by someone I didn't know so I went to look and... it was her. She immediately unliked the picture but it was too late, I got the notification on my Apple Watch.
As if she is STILL lurking on my stuff! She's not said anything that I know of and even if she had, I really couldnt care less. I'm not sure if I should make my Instagram private so she can't go through it anymore... or if I should just let her keep lurking with envy? Happily married, we own a property together, we're having a child... maybe I should just let her watch? That sounds mean I just... I can't help but find it a bit funny after everything she said initially. 😌