After a hysterectomy during childbirth, the author and her husband considered adoption or fostering while raising their young children. When their sister-in-law had unexpected twins, she and her husband struggled with parenting and asked the author to take in the twins. After discussions and counseling about their situation, the couple agreed to adopt the twins, resulting in a legal agreement where the sister-in-law surrendered her parental rights.
https://slate.com/advice/2024/10/sister-in-law-twins-adoption-parenting-advice.html