Lord, have mercy! That isn't the easiest of surgeries. I pray she has a quick and easy recovery.
Growing up my mother was always wanting to have more children. She had her tubes tied right after delivering me. My step father had a vasectomy before he met my mom. Even when my husband and I have thought we were "done" having children I have been reticent to do anything permanent. I have seen too many people that later changed their minds about children.
May the Lord bless you with some beautiful children soon!