Have a healthcare practice question?

Yes, but since they can not discuss their patients they would never know.

It is the patients choice. They are free to pick other doctors

Your question is unclear. If there are multiple doctors in a practice (whether they are husband and wife or otherwise related) you can be treated by any doctor in the practice at your choice.

Sure they can. What is usually not done is a doctor (especially a surgeon) treat a family member - very different.