Mieke Verstraete

From Muppet Wiki

Mieke Verstraete played Magda on Sesamstraat, the Dutch co-production of Sesame Street, from 1978 to 1982.

Magda is Piet's sister. She was the first grandmother character on Sesamstraat.

Mieke was the first actress who appeared on the show under a different name. She left the show in 1982. Paula Sleijp took over the grandmother role.