There is a E. Timmer with telephone living in Emmer-Compascuum. It's normal for widows to keep the name of the family in the telephonebook. Here the link: http://www.detelefoongids.nl/tg/plaats-emmercompascuum/w-tim...
. On Google maps you can find the house (unfortunately no Google streetview) and from above it looks like appartments (for elderly people?). I hope, it's the right mrs. Timmer.