"She loves her husband."
Translation:Hun elsker sin ektemann.
"Sin/Sitt/Sine" points the ownership back to the subject of the sentence, which in this case is "henne". So "Hun elsker sin ektemann" means that she loves her own husband, while "Hun elsker ektemannen hans" means that she loves somebody else's husband.
The English sentence "She loves her husband" is ambiguous, and can translate to either of the Norwegian versions.
"Borrowed from German echt (“real”). The German term originates from Middle Low German echt (“lawful, genuine”), contraction of ehacht, variant form of ehaft (“lawful, pertaining to the law”) from ê(e) (“law, marriage”)."
In this lesson, we teach it as a prefix in "ektemann", "ektefelle", and "ektepar". In that context, it can be understood as "lawfully wedded" in English, but you wouldn't explicitly translate it as such outside of your wedding vows.
"Ekte" as a standalone adjective, meaning "real" or "genuine", is taught in Adjectives 3: lesson 5.