This is an 18th-century painting by Louis Léopold Boilly. The young lady is straddling a bidet while washing her genitalia. Since I've never had even an Art101 course, I was a little surprised that this would be the subject matter for a salon-exhibited classic era painting. A glance at Wikipedia turned up this relevant information:
Boilly was a popular and celebrated artist of his time. He was awarded a medal by the Parisian Salon in 1804 for his work The Arrival of a Mail-coach in the Courtyard of the Messageries. In 1833 he was decorated as a chevalier of the nation's highest order, the Legion d'Honneur.
At the height of the revolutionary Terror in 1794, Boilly was condemned by the Committee of Public Safety for the erotic undertones of his work. This offence was remedied by an eleventh-hour discovery in his home of the more patriotic Triumph of Marat (now in the Musée des Beaux Arts, Lille) which saved him from serious penalties.