May I know all Gabby's ending? I only got 1
There's the Friend Ending, obtained by turning Gabrial down; there's the Friends with Benefits ending, obtained by not raising Gabrial's trust enough throughout the quest for her to confess to you properly; the Commitment Ending which is reached if you have decent trust, or max trust but fail to convince her to have an open relationship and thus while you end up together she doesn't approve of any other partner you may have; the True Ending, which needs max trust and ends with her accepting that you may be with other people; and then there's multiple bad endings, though they count as a single ending (because they all end up with no more Gabrial content.)
Almost every single choice during Gabrial's route goes towards raising her trust stat, so it takes a bit effort to achieve the true ending, but it shouldn't be too hard to achieve at least the Commitment Ending even on a first playthrough.