This is not very little. He only works 20 hours a week (or 4-5 hours/day). He can easily make $200+k if he works twice as hard. He probably doesn't have any student loan and his wife makes $260k. Don't feel bad for him. He is actually in much better financial shape than you and me when we graduated. Unlike us, he doesn't need to worry about working hard to pay back loans and to save for future retirement. In 6 years, he'll be the owner of the million dollar practice. If I was in a similar situation like his, I would take things easy as well.
My wife now only works 2-3 days/week, 2-3 hours a day because we already paid off our debts and I still work full time. Taking care of kids is our #1 priority. My wife doesn't want to retire and be a full time mom because she actually enjoys working. The job is more enjoyable because she no longer needs to go around begging the GPs for referrals, to sell cases, to worry about the overhead and about paying bills etc. That's her reward for working hard when she was in her 20s and 30s....and for marrying the right guy (me)😀.