I Became the Mother of the Strongest Demon Lord's 10 Children in Another World is a Manga/Manhwa/Manhua in english language, Shoujo series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

High school girl Akari mourns the loss of her mother who died when she shielded Akari from an oncoming truck a year ago. She discovers an adventure game her mother had gotten for her birthday some time ago, but never had a chance to finish. Suddenly, she is summoned to be the mother of the Demon Lord’s 10 children in another world..