I get that a lot, actually. I don't really ming being a "career student" though. In fact, I really think it's great. I love reading, learning, arguing, and hanging out with other people who don't just put up with my history-dorkiness, but will engage in lively conversation about it. By continuing school, I'm not avoiding the "real world," I'm just involved in a different kind--preparing for a different kind of life.
Does she regret not finishing her degree? Is she stuck in a kind of "life rut" she can't get out of? Obviously, I don't know anything about her or her educational history, but I have generally found that when a person make comments like this, it is likely in response to his/her own issues (whether s/he is cognizant of that or not) rather than a critique of your plans and decisions.
What I personally find most difficult about these situations is not offending them. People tend to regard some graduate students/PhDs (and I find this most prevalent if continuining in the humanities...) as stuck-up and elitist.