I cannot find anything about her besides this note accompanying this portrait:
"The inscription, which retains its original layer of shell gold, identifies the sitter as the wife of a Thomas Potter, and being aged twenty-three in 1565. On 14th November 1559, a Mary Tichborne of Edenbridge married Thomas Potter of Well Street at Westerham Parish Church in Kent. This Mary was the daughter of Richard Tichborne, and born in 1541, so must be the sitter in the present portrait. Her mother was Thomasin Tichborne, née Seyliard. The Tichbornes were originally a prominent Hampshire family, and we can judge from Richard’s subscription of £5 towards Henry VIII’s ‘Loyal Loan’ in 1542 that he was relatively prosperous. A monument to Thomas Potter at Westerham records that he was a Justice of the Peace in Kent for 'about fifty years, continuing the whole course of his like liberall and bountifull to the poore, constantly and painefully studious of Divinitie, Law, and Phisick…' The monument, which features a figure of the kneeling Mary Tichborne, also records that she was 'a very religious and virtuous gentlewoman'. They had four children; a son Nizell, who died at the age of 21, and three daughters, two of whom, Lucrece and Ursula, died in their infancy, and Dorothy, who married Sir John Rivers, 1st Bt (1579-1651), the son of Sir George Rivers, sometime MP for East Grinstead during the reign of Elizabeth I."
From pinterest.com/lb3038/historic-embroidery-in-paintings/blackwork/.jpg.
The bodice has a very high collar while the opened partlet ends in a ruff that surrounds her face.
Keywords: 1565, Master of the Countess of Warwick, Mary Tichborne, Mary Potter, Tichborne family, Potter family, English, straight coiffure, attifet headdress, veil, split partlet, high enclosing neckline, neckline ruff, necklse, fitte bodice, high collar, vee neckline, pendant, rolled cap sleeves, long close lower sleeves, blackwork, tight cuffs, ruffled cuffs, vee waistline, A-line skirt