нашла американский первоисточник перевода, там автор объясняет эти эффекты увеличением дохода:

"For some families, having a mom on the job is better for children, according to the meta-analysis of 69 studies conducted between 1960 and 2010. For example, children from single-parent or low-income families whose mothers worked had better academic and intelligence scores and fewer behavioral problems than children whose mothers did not work, the authors found. This was probably due in part to increased resources that the income afforded, they said."

Забавно, что в немецкой статье выше авторы взяли из американского исследования только то, что им подошло идеологически, а неподходящее замяли, назвав негативные последствия для остальных детей "profitieren nicht so stark":

"In particular, early maternal employment was significantly associated with positive outcomes (i.e., increased achievement and decreased behavior problems) for majority oneparent samples. However, early maternal employment was associated with negative outcomes for other subgroups, namely with decreases in achievement for two-parent families and increases in behavior problems for samples with mixed one- and two-parent families."

https://www.apa.org/pubs/journals/releases/bul...