Hello, psychic medium here. :)
I am not a grifter. I am not delusional. My husband is a doctor twice over, and my friends are normal down to earth people. I have a bunch of pets, I enjoy helping people, and I have a rather high IQ. All of that is just to say that I am basically "the psychic medium next door." I call myself a kitchen table psychic. Most of the psychics you will meet in real life are just normal, down to earth people like me. The only difference between a psychic (a true psychic) and yourself is that a psychic has learned to tap in to (psychic) energy. It's just like when you think of someone and then they call you, or you pick up "vibes" from certain people around you. It's the same thing only more focused.
Psychics are not right 100% of the time, just like any other professional person is not right 100% of the time.
One important thing about future predictions is that everyone has free will. And they can change their minds and do something else at any time. Which in turn can change the future, even for someone on the periphery of those decisions. I know it sounds like a cop-out, but energy is constantly evolving and changing and affecting the world around it.
Your brother in law should possibly have not asked about your husband. I feel he only did it because he cares and wanted to help. If this psychic is correct about what she said about your husband, there may be a way forward to help him learn to open up. If she was not correct at all, just ignore it, and move on. No harm, no foul. Maybe let him know that you'd prefer he not discuss you or your direct family with psychics as it's not something you believe in.
Obviously, this isn't for everyone, and that's ok. I do feel that if people were taught to trust their instincts more, and to speak up when something feels off, there would be less crime and pain in the world. I wish children were taught to listen to that little voice inside, and to act on it, and maybe even to tap into the energy we are all connected to.