So let's see what we have here.
We have a hypothetical version of a character vs someone who is quite casually stronger than everyone in her universe combined by a great margin.
So already by implying that this hypothetical Orihime can best Broly you are placing her heads and shoulders above everyone in her universe. Including Aizen, Ichigo, Yamamoto, and the combined might of the Gotei 13. If Orihime were ever capable of such power then why would Aizen not bother trying to harness it for his own use?
The argument you're presenting is already stretched because of the above(if not broken completely) but besides that you are facing an uphill argument by using a hypothetical. Point black Orihime has never used her rejecting abilities to destroy something significant, let alone someone like Broly. The closest we get is her wanting to destroy Aizen's pet rock and if she can't will it out of existence by just wishing then she will do nothing to Broly.
And of course Broly is far too fast for Orihime and her fairies to touch. And since he's started this battle enraged he would likely just kill her before her hairpins have time to glow.