Do yourself a favor and don't keep your wife in the dark. From all my experiences, this is a bad thing to do. Most women will be more supportive if they know where you are and what to expect if things get bad. Just show her that you are working your ass off. If she can't be ok with that and helping you achieve your goal, then she's not worth having around.
Just my 2.38 cents
Just my 2.38 cents