Complex sentence: She published one of her first stories "Pleasures of Factory Life" in an 1840 issue of the "Lowell Offering", a literary magazine written, edited, and published by working women, some of them very young.
Split into simpler sentences: She published one of her first stories "Pleasures of Factory Life" in an 1840 issue of the Lowell Offering. The "Offering" was a literary magazine written, edited, and published by working women, some of them very young.