Follower of Antoine Pesne

The canvas is unlined. There are a number of repaired tears as follows: - a 28 cm. repaired vertical tear, lower right - an 8 x 6 cm. t-shaped tear centre right - two horizontal repaired tears upper centre measuring 18 cm. and 10 cm. respectively - a small tear to the sitter's right shoulder - a 4 x 5 cm. inverted L-shaped tear lower left - a 9 cm. vertical tear to the left of the sitter's neck - an 11 cm. tear to her bodice - two repaired tears upper left, measuring 6 and 4 cm. respectively - a repair in the sitter's skirt, measuring 5 cm. The vertical seam of the canvas is widening slightly in the centre, but this is not a major cause for concern. There are a total of 15 old patches of canvas affixed to the reverse to mend some of the aforementioned tears. Inspection under ultraviolet light shows repairs to many of the aforementioned tears, and a small patch of repainting on the left of the chair, measuring 5 x 3 cm. This lot is offered in a gilt 18th century German gallery frame, in stable condition. For all sales which take place on or after 1 February 2015, please note that the rate of buyer's premium for each lot (charged as a percentage of the hammer price achieved for that lot) has been revised and shall be calculated at the thresholds set out below: Buyer's premium is 25% of the hammer price up to and including £100,000; Buyer's premium is 20% of the hammer price on any amount in excess of £100, 000 up to and including £1,800,000; Buyer's premium is 12% of the hammer price on any amount in excess of £1,800,000. As stated above, the revised thresholds are effective as of 1 February 2015.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

The picture is by tradition said to depict a sister of Frederick the Great, King of Prussia (1712-1786).  Frederick had three sisters, Wilhelmine, Anna Amalia, and Louisa Ulrika who became Queen of Sweden between 1751 and 1771.