I to believe that you should have one tree for you and your wife. As said earlier you never know when the trees will cross.
It also removes the need for duplicate updating, especially for your children. nephews, and nieces.
If the database is so large that the genealogical software can not handle the database, you may consider make three database. For the husband family, for the wife's family, and and your children's family. This would minimize the necessity of duplicate updating, but does not prevent the children from marrying a distant cousin.
With a combined database you can report out the parts that you are interested in. I don't share my database, but will gladly provide reports from it.
I use the FTM books to share the subfamilies. They are very versatile as to what you place in the book and can be tailored to the person with whom you are sharing the information