I'm married with 3 children and a senior in dental school. I also am older than most of my class. When we were facing this concern of time with family during school, I found it helpful to see what the schedule might be like. My schedule during the first 2 years was this:
Sunday: no studying; all family/church stuff
Mon- Friday: school from 8AM - 5PM (study between classes and over lunch)
5-5:30PM - 7-7:30 PM Family dinner and family time
7:30 to 10 or 11PM (study) except Friday
kids usually in bed by 7:30PM; sometimes back to library or school for studying; sometimes at home.
Friday night is date night with my wife
Monday night family time is sometimes extended
Occasionally on a finals week, I would get up really early (3:30-4AM), go to the library and hit the notes hard
🙂sleep: ) for 4 hours straight before a final to supplement the other studying.
Saturday: 8-5PM (study, lab-work, practice preps, etc.)
During my 3rd year, studying went down and lab work for patients took some of that place. I also got a job working Wednesday evenings and Saturday mornings at a dental office assisting.
Now I just lay around eating my kids Halloween candy worrying about how my interviews for OMFS are going to go.

I got most of my graduation requirements done the junior year.
Finances: my wife raises our beautiful children (4
🙂 , 2.5
😛 , and 7 months

) in the home. I take out loans for school and make a little money on the side. I apply for scholarships and have received an Evalee Schwartz interest-free loan 2 years straight. If I were going into general dentistry, I would do public health in a high need area and make over 120K right out of school. No problem paying back the loans if it is a proper priority.
Bottom Line: If you are a procrastinator or will be--you won't do well in dental school. If you are gifted, as most dental students are, you will still pass. If your wife is "high maintenance" about needing a lot of time with you and doesn't really support you putting in the time you need to become a good doctor of dental surgery--I personally would explore other options. Dental school would be very frustrating under those conditions.
A dental admissions guy told my wife that if I went to his school, I would be at school from 8AM-5PM and 7PM - 11PM or midnight. I asked her if she could handle that schedule for 4 years before going ahead with it. Most of the time, the schedule isn't that bad, but if you follow that routine you are sure to do really well.
😉
With my schedule, I ranked #1 in my class (wasn't planning to specialize until this summer
😱), scored a 96 on Part I, and yes my wife still loves me and my kids know who I am. Good luck

with your joint decision with your wife.
P.S. My wife read this before posting and added all the smileys