As the saying goes, blood is thicker than water.. What a bunch of lies.. Then the saying that God is love, God's promise unchanging?? I used to believe it.. Not anymore..
I have other family members to turn to.
Bad situation where the mom didn't apparently think things through or remember her commitments. But you ask if you should stick to your guns. What guns? What are you hoping to achieve? You have a right to be mad, so be mad and demand an explanation. Totally put your feelings out there. But don't hold a grudge regardless of the outcome. They are family, just demand you all duke it out.
Till YOU give an apology???? Something is wrong with this picture.