You indicated that the faculty did in fact find existing content. That is excellent news!
Now consider: Does your faculty member want to adopt or adapt the resource?
Adopt means faculty will use the resource outright, with little or no changes to the content. This may be the way to go if they are truly happy with the resource or if they are just getting their feet wet. They can always try it out and make changes in later semesters if they want.
Adapt means they will be using the resource, but also adapting it. Perhaps they will add in an extra section of their own writing (to make it more relevant to their student demographic), or they will take out significant parts of an existing chapter. Either of these (and more) are excellent reasons to adapt a resource, rather than simply adopting it.