B.D.
My daughter is allergic to dairy as well. I typically do not need to cook two meals. Whenever possible I substitute rice milk when a recipe calls for milk. I also substitute either Earth Balance or Fleishmann's UNSALTED margarine for butter.
I avoid recipes that call for cream of anything soup.
As for cheese... You need to watch. Some that you'd think are dairy free (Veggie Slices or Rice milk slices) still contain casein. My daughter uses Tofutti slices for sandwiches and Daiya shreds on pizza. I've read that the mozzarella flavor is the least 'offensive'. With that being said, THAT is where I draw the line with eating the same meal :-) If I had to go dairy free I would never eat 'cheese' again. The smell and taste of the non-dairy cheese is just nowhere close enough for me. I'd rather go without. Tonight I made nachos. I made one plate with Daiya and a plate with regular cheese for the rest of us.
I make my own breadcrumbs from the leftover heels of dairy free bread. If I want them to be Italian flavor I add the Italian formula of Mrs. Dash.
I buy Heinz pork gravy and Campbell's turkey gravy.
I'm 7 years into this so I'm sure there are other adjustments I make that I'm just not thinking about right now. If there is anything specific that is giving you trouble, PM me and I will let you know if I have found a solution.