Most sets of twins - same mother
Who
Mrs. Vassilyeva
What
16 people
Where
Russian Federation (Shuya)
The first wife (died ante 1770), of Feodor Vassilyev (b. 1707–c.1782), a peasant from Shuya, Russia, gave birth to 16 sets of twins.
Barbara Zulu of Barberton, South Africa bore 3 sets of girls and 3 mixed sets in seven years (1967–73).

Anna Steynvaait of Johannesburg, South Africa produced 2 sets within 10 months in 1960.