Well, the $1000 is ridiculous, obviously. It would depend on which model it is, and how common that model is. Without knowing those things, I'd say if it's in a nice table and in nice shape, give her $100 for it.
I have a Singer 66 treadle from 1918, with lotus decals and in a beautiful parlor cabinet (not just a table) with an elevator lift. Both are in lovely condition. I paid $135 for it at a flea market, because of the cabinet.