Yeah, that's spam commenting. Stalking would be more if she's also commenting on your Facebook page, she found you on Instagram, someone called for you at work and they found the phone call suspicious as hell, things like that.
Abusing the comment feature on imgflip is just a form of spam.
People like timby and chosanwan call it stalking but they're wrong about everything so there's no need to take that seriously in any way.