Weiss Gallery’s notes provide the only biographical information I could find, "Little is known of the sitter other than her traditional identification as ‘Lady Mary Parker, née Senhouse’. This appears to have been a hybrid identification, muddled over time through the family’s subsequent generations; the Mary Senhouse whose dates fit with our sitter never married, (though there was a Mary Parker, née Senhouse who married in 1819). The Senhouses were a prominent Cumbrian family and Lords of the Manor of Ellenborough (also known as Alnborough).[4] Mary was the twelfth child (of fourteen) of John Senhouse (c. 1540 – 1604), of Netherhall, and Anne Ponsonby of Haile Hall, Haile, Cumberland. Here, aged thirty-three, Mary wears a black cap and mourning thread around her neck. These were most likely in remembrance of her recently deceased father. Her sumptuous buff coloured dress is enough to tell us this is not a portrait of a widow, as for example, in Marcus Gheeraerts’s portrait of Elizabeth Finch in widow’s weeds (painted 1600, private collection).”
From pinterest.com/jkrystyna82/16th-17th-century-rebatos-standing-collars/.
Weiss Gallery’s notes also state, "She is depicted wearing a striking buff coloured satin dress with elaborate silver embroidery, buttons and spangles, though perhaps the conspicuous lack of jewellery may reflect her unmarried status.”
Keywords: 1605, Peake, Margaret Senhouse, Senhouse family, British, high straight coiffure, lace headdress, cap, chemise, high vee neckline, lace-edged neckline ruff, fitted tabbed bodice, vee neckline, buttons, tabbed long tapered false sleeves, lace-edged back-flared sleeves, vee waistline, wheel farthingale