I seem to always be the one to jump in with my comments first, so here I go again.
What you have stated happened is a lot of what happens when you do genealogy research for your family and folks want you to either do their family research or give all of the information to make a reunion as successful. It is actually a compliment. But what you can do is SITE all of your sources. Guide them and step back and let it happen. Give them titles of books and places to go to make theirs a success. Usually it's a time limit they need all of this, not 2 years down the line. If this doesn't work, pray on it and then do what you got to do.
Either way you will either loose a friend or gain respect for your hard work. Good Luck.