Your search for "Scribe A" returned 24 letters.
Bess (dowager countess of Shrewsbury) writes to William Cecil, Lord Burghley, regarding troubled negotiations with her stepson and son-in-law, Gilbert, seventh earl of Shrewsbury, 'in respect of my widow's part'.
Bess (dowager countess of Shrewsbury) writes to the earl and countess of Shrewsbury (her stepson and son-in-law, Gilbert, and her daughter, Mary), enquiring after their and the children's health and telling them of her own; advising them to come into the country where the air is better than in London. Also, she is assured that Master Winter has no right to 'the ground [he] pretendeth title to'.
Bess (dowager countess of Shrewsbury) writes to the earl and countess of Shrewsbury (her stepson and son-in-law, Gilbert, and her daughter, Mary), wishing them well in a suit they plan to undertake the following Monday. In a postscript to Mary, she expresses her sympathy that Charles (presumably her son and Mary's brother, Charles Cavendish), is still ill and asks her to write and remind him to 'keep good diet'.
Bess (dowager countess of Shrewsbury) writes to her daughter, Mary, countess of Shrewsbury, asking her to write with news of her and her family.