My spouse didn't know enough about the WLS process in order to know about supporting the idea when it came up. Fortunately, it was not originated by me, it was by my PCP, but there was still a lot of hesitation. I actually had to play it cool for a few months until the idea gained traction.
She would ask me if I had thought about the decision and I would be like, "I"m just going to go to the nutrition sessions and learn more, you're welcome to come along" and any possible moment that I could get her there, I would always make it feel like her decision. After a few months of this, I finally saw my moment and took it. She was totally on board by then, but had I not been patient through the whole process, pardon the pun, I don't think I would have gained the support I received and still have to this day 7 weeks post-op.
I hope this helps, good luck.