Mothers rings are a gift given to celebrate the mom in your life. These types of rings are commonly given on the day to celebrate all mothers: Mother's Day.
Mother's Day originated in the United States about 90 years ago with a woman named Anna Jarvis. Anna wanted to honor her late mother with a special day set aside just for her. Anna convinced her church leaders to talk about the importance of being a mom on a specific date in May. She then founded the Mother's Day International Association which then followed with Woodrow Wilson proclaiming that the second Sunday in May was to be Mother's Day and should be observed nationally.
Of course, people starting purchasing gifts to celebrate their mom's and many started giving their mom jewelry with the birthstones of Mom's children on it. This in turn, became a Mother's Ring.