I have said, and shown, that tiredness and busyness are major destroyers of sex for women, and since margin is all about being less tired and less busy this is a natural fit. However, it is more than just a better opportunity. One common complaint from wives is their husband rushes to have sex, and then rushes the sex. She wants more non-sexual time before sex, and she wants to move slower when she does have sex. Margin allows you to do both without worrying you will run out of time before you get to the sex!
Margin also gives you the chance for some unplanned spur of the moment sex. I know, I know, your wife is not like that. Maybe she is not like that because so many of her needs are unmet sex never sounds good. More margin in your marriage should result in more of her needs being met, which can make for a lot of great changes – including sexual changes.
For this to work you need to convince your bride to add margin to her life – both her life in general and her time with you. I know I’ve already pushed the book a couple of times, but let me say Margin may be one of the best marriage books out there (even though it is not intended as a marriage book). I suggest you get it and challenge your bride to read it and discuss it with you. I am so sure of this I’d say do it even if you have to agree to read a book of her choice as well (and do her book first!). Don’t tell her you want her to read the book so sex will be better, just tell her you think the book will help both of you and your marriage. (Maybe your suggesting a book that is NOT about sex will impress her!)
At the very least more margin will mean a more relaxed relationship, far less stress, and lessarguing and picking. In and of itself that is good, and it can only help make sex better.