Sentence:  The latter is her “<WSD>outside</WSD>” child in reference to her conjugal tie at the time. Should she leave this man and move in again with the father of her first child, then the three younger children assume the place of “<WSD>outside</WSD>” children, [...] 
Meaning of the word marked with <WSD> tags:  Not legally married to or related to (e.g. not born in wedlock to), and/or not residing with, a specified other person (parent, child, or partner);  existing between two such people. (out of wedlock), (nonresidential).