the intended audience isn't you or any married couple. the intended audience of her song are single mothers. that's the reality of the situation, and she's giving them a song to feel good about.

there's nothing wrong with that. its not like someone will here the song and be like "wow.. this single mother thing sounds great!! i'ma try it out for a year"

«SiG»
“Stand out firmly for Justice as witness before God, even against yourselves, against your kin and against your parents, against people who are rich or poor. Do not follow your inclinations or desires lest you deviate from Justice."
-Qur’an 4:135