Balclis, from Spain, sells on 25 October a "School, probably Dutch, 1700" portrait of a lady and her son, estimated at 5,000 Euro. The surprising small work (41 by 33 cm, it looks life-size in the photo) has a tentiative attribution to Caspar Netscher or Jan Weenix.
In my view, this is a French work. The headdress is a Fontange, the dress is a Mantua, and this combination was for a short period (1690-1710 or thereabouts) extremely popular among the very wealthy French aristocracy, while being virtually absent in other countries.
I have been unable to identify the sitters or the artist, but the work is nevertheless very interesting as a piece of social history, depicting a peculiar but strangely impressive bit of fashion. There are many engravings showing this mode, but relatively few full-length paintings, and then they usually focus solely on the woman.