>>82756209A lot of this is personal, so take it with a grain of salt. Still:
1. Put more emphasis on her flaws. I find it hard to relate or care for characters without clear issues. Have her mess up, slip up, say stupid things, and be clearly awkward more often. (Nothing too cringe, though, or at least not more cringe than her writing smutfics about the Alpha kids. That's already top cringe.)
2.
>>82756256 is right. Make her less of an exposition lady and more of a hilarious, loveable dork. Caliborn is funny! Why? Because he's ridiculous, overdramatic, and oddly clever in his insults and his plans. Take some inspiration from that.
3. Another thing that bothers me with Calliope is that she's involved in Homestuck's plot by existing, and only because of that. She's related to the big bad and prophecized to be a secret weapon against him and that's all. Otherwise she mostly stands around acting cute and being a goal for Roxy. She's a McGuffin made flesh, and that sucks.
Now that doesn't mean she needs to fight LE or gather up an army or do something important. She can stay on the sidelines. But her appearances need to be interesting, and for that I see two things that could be focused on:
a. The way she deals with her confidence issues after Caliborn's bullshit wears her down. She wants nothing but happiness, doesn't she? It should not be cast upon her like a blessing from the sky. It should drive her. She can't be the melancholic skull snake girl forever.
b. Her desire and attempts to interact with the heroes she loves so much. Seriously! She grows up being obsessed with them, but her conversations are almost exclusively with Roxy. I want to see her talk to Rose and Terezi, to Dave and Tavros, to Nannasprite. Roxy and Calliope's adorable interactions get boring after the eleventh time.
c. Her role as a muse. She's basically THE passive booster, right? So have her try to give some emotional support and make her kind words have some impact.
Things like that.