Nobody touches my woman's hair but me! When it's time for a trim, I do the "honors" myself. If you work it right, it can be quite an experience for both of you. I have had a comb in one hand, scissors in the other, and my dick in her mouth as I straddle the chair she is sitting in while I'm combing out her hair!
And she quite enjoys it when I shampoo her hair in the sink before the trim, massaging her scalp in the warm spray of water. Of course, the first time was the hardest, convincing her that I could do it (I dated a stylist for a number of years, and cut her hair also - she gave the best hairjobs I've ever had!!).
Maybe you could get yourself an instructional video on home haircutting. Or even rent one at Blockbuster, there are tons of them out there. Then let your lovely wife know that you want to help her in caring for her hair as she grows it out for your pleasure. I think you might be amazed at the fun the two of you could make out of it!!! Please, let us know if you have any success! I for one, would love to hear all about it!!!