I interviewed for MD/PhD this year, and it seemed like having a family is difficult while training, but not impossible- at least 2 students at each interview day I went to had children. I got the impression that it would actually be easier to start a family during your grad school years (typically years 3-6) than it would be during M3/4 or residency.
I think you would be competitive for MD/PhD programs, however it may be difficult to justify why you want the PhD if you don't plan to focus on research. The 'classic' MD-PhD aims for 80-20 split for lab to clinic time.
Doing the MD-PhD for financial reasons is imo, not worth it. You don't have loans, but you miss out on at minimum 4 years of earning. MD-PhDs also typically go into academic medicine, with lower salaries.
As I am just starting my MD-PhD journey, I can't offer much advice on long term career paths- but what I did when I was trying to figure this out was just cold email people in my institution and ask if they had time to chat about their career path. Look for clinicians who do research and see if they'd be willing to talk to you about it.