I'm 35, got my MA in religion in 2011, and am applying to PhD programs this year. My husband was at the same grad school I was, but he did a dual masters that took 4 years (mine took 2.) Then he got into a really good PhD program in an area of the country where I couldn't find programs in my field. I wasn't thrilled, but it was a great opportunity for him, and I needed a little time to think about what I wanted to do (career-wise and research-wise.)
Now he's in his fourth year and has one to go, but I'm applying to PhD programs now. Wherever I get into (if I get into...), I'll go there this fall, and he'll follow me next year. So there has been a give and take. He was also willing to limit his internship search (he's in clinical psych and has to do a one year internship) to the area of the country I'll be in, which is a sacrifice for him, but that way we'll only have 9 months to a year apart instead of 2 years apart.
I think we both made our decisions out of love and caring for each other, and not out of obligation or pressure from one another. We've both had to sacrifice, but the happiest couples I've known had their own separate lives in addition to their marriage. You have to find that balance between yourself and your relationship, and you have to let your partner be free to find that for themselves as well.