Well... modern Japanese harem terminology differs from the court harem terminology.
rather than debate about it, how about just following the tags officially attached to it from Japanese publishing company?
Well, if there is a tag for a proper harem, i won't really care whether it has a word "harem" in it or not.
Ahhhh we defo know what happened if she wasn't thrown away.... spicy tag an all
While the possibility is there, we know she was supposed to be pushed off a cliff just like MC (and most likely into the same valley), and we see her at the cliff surrounded by soldiers (looking like their souls are getting sucked out by Saint-girl's powers, newly granted by the Eyeball). She could've just escaped after that.
About her denying the Eyeball being involved, it's clearly obvious that she isn't fond of this power. I guess, she hates it so much, it just didn't click with her that the fact that Tetsuya is aware of the Eyeball and still alive and kicking after being brought to the same cliff means he's got an Eyeball-related power as well.
On an unrelated note, it's hella cute how she's happy about him not being just another fan of hers.