Yes. Maybe they will think about getting married now,
so their baby will grow up thinking ‘my dad loved my mother enough to marry her’.
Wouldn’t that be nice?
Your point? Though unmarried, these two are far more legitimately parents in every sense of the word than the legions of married couples who legally rid themselves of their children—and I dare say, more legitimately parents in the eyes of God as well. The same UK body of law that bestows “legitimacy” by marriage license also bestows legitimacy on the taking of pre-born life.