For those who are saying its a ring, look again, its not wedding ring. She has it for both hands at the middle finger and tied up by some string.
Open the spoiler for dancer outfit sample, watch her hand carefully.
The loli also wear the same accessory, probably that world fashion.
For those who keep thinking that she is the biological mother, chapter 1 page 6 clearly stated that she is the adoptive mother, so yah she dont literally give birth to him.