You asked for honest opinions, so...
Honestly, depends on the age.
If it's a teenage unwed mom, I tend to look down on them (though I know it's wrong for me to judge) for having gotten pregnant in the first place. It's so easy to prevent that: JUST DON'T HAVE SEX! So at that age, I tend to look down. Or if the kids are old enough compared to the mom that it was "obviously" a "high school" pregnancy, same thing.
At older ages, it's more a sense of "what happened". Did the dad walk out? Did the dad die? Did the mom leave and take the kids? Was it a case of not being married and having sex?
If it's a case of being unmarried and having sex, I look down on that because *to me* having sex without being married is morally wrong. I know that opinion in the minority now (or seems to be), but that's my opinion.
If it's a case of a divorce, widowing, or abandonment, I tend to feel sorry for the mom rather than look down on them. And if it's a case of the husband walking out or the mom leaving an abusive situation or similar, and the mom obviously raising wonderful kids on her own, I'm proud of the mom.
So it can really vary.
Note, though, that looking down on them isn't the same thing as *condemning* them. Unwed moms and some teenage moms can sometimes be better than married moms. I just think the unwed ones who got pregnant before getting married made a bad decision.