I have searched 半ば meaning and translation, but I couldn't find an example that fit in with the sentence that I read on the light novel.
From jisho.org, 半ば: 1. middle; half; semi; halfway; partly
Then I found an additional info from weblio.jp that might be fit in with the above sentence.
- ある状態に半分ほどなっているさま。 2. かなりな程度。ほとんど。
So, can I translate the sentence as follow:
"It was almost like a provocation by Nagumo, but in reality Horikita who should have come to this school to follow her brother, had only been able to get in touch with her brother for a short time so far."
Thank you for your kind guidance.