Really? I found romancing her to be the easiest of them all
She is quite tricky to romance if she refuses to join your party.
True. Being gith and trying to bone shadowheart supposed to be some kind of an oxymoron though
I have been playing as a wood elf and she refused my party too, because Lae'zel was already in it. You don't need to be a Gith yourself for her to refuse.
(In my case, I don't want her anyway, since my main character is a cleric. So not a problem.)