Your ignoring one basic Christian fact.
What would Jesus do?
Would Jesus not make them a cake or will he make them a cake.
Will he treat them different or will he treat them equal.
As with the prostitute who was being stoned, He would Bless them and say “go and sin no more.” He had that power. I’m not arguing what is the ultimate cause of homosexuality, but God does know. We do not. His power is greater than ours.
I’ve cut your post only to make this not so long. But, it’s not only through the Bible and Scripture that we know and follow our faith. We, as Catholics, are also subject to the teachings of the Church – His Pope, the Magisterium, etc.
The question is the woman’s conscience as she sees it. She followed her conscience. We cannot judge her based upon Scripture alone. She felt that creating a cake was, by extension, a participation in an event that the Church teaches us is wrong.
You must look at both sides of the issue. If the woman was following her heart, as she undertands the teachings of the Church, we have no right to judge her decision. Some may view the cake as not taking a part in validating a marriage – it’s just a cake. Some view the cake as a symbol of the validity and participation in what is termed a “marriage”, something that our Church teaches us is a sacrament and taken in a state of Grace by a man and woman.
I don’t judge homosexuals either because only God can judge. There are many who remain chaste and are within God’s Grace, as much as anyone, just as heteros are not to engage in sexual relations outside of the sanctity and sacrament of a sacramental marriage. There’s no difference in that.
I advocate for tolerance since only God knows the reason why people are drawn to their own sex.
However, I don’t know how far it is before tolerance is viewed as particpation in an event – she would have been a remote third party and not in attendance. Not that attending that wedding is going to turn someone homosexual, but because if, by making the wedding cake, she may have felt she was given legitmacy to the marriage against Church teachings and her conscience.