Finally, Riri's mama has a given name! Rie.
I can definitely see the name Riri being derived from Rie. So what's left for me is to know if Tobe is her maiden surname (she reverted to it after the divorce which can happen in Japan) or her ex-husband's family name which she and Riri kept after the divorce.
Also, that rare smile at the end. She's really proud of her specialty, and by Riri's joyful faces here and in 127 it should be really good.