Very cute, but inaccurate in one major detail. I do believe hornet has been confirmed to not be one of the "siblings" in the same sense as those created to become hollow knights. She was a child given to the beast queen hera as compensation for her sacrifice to become a dreamer.
The relevant detail here is that they are just half siblings. A bit nitpicky but it does matter lorewise. Just a bit.
Edit: it could also be that hornet didnt want to bother explaining the difference, and she just wanted to introduce them in a more understandable way.