Look up the term overthinking
in the dictionary. You should see a picture of yourself there.
Srsly, er, so what if her follower number changed?
It. Means. Nothing.
PS You don't need to summon up courage to send her a social media request, FFS. Say, "Julie (or whatever her name is), I just want you to know that I'm following you on social media because I think you've got interesting things to say."
Frame it as a fait accompli
, that you're already doing it. You don't need her permission to follow her; you're just telling her so she doesn't (for whatever idiotic reason) freak out about it. And she shouldn't. If she's saying anything private, then she can either block you or change her privacy settings.
It's social media. You're not getting on one knee. You're not going into battle. You don't even have to tell her that you're following her.
To quote Nike: just do it