Your search for "Bess as mistress: letters between Bess and her servants" returned 29 letters.
Hercules Claye, a servant, writes to Bess (countess of Shrewsbury) to report how 'at York assizes all things have proceeded against master Basford [i.e. Beresford]', with detailed information regarding those present.
Robert Dudley, earl of Leicester, writes to let Bess (countess of Shrewsbury) know that the queen thinks her and her husband, George, sixth earl of Shrewsbury's servant Marvin should be removed from their household because of his suspicious behaviour. Note: A reply to this letter (also a copy), by Bess's husband, exists adjacently in the same manuscript volume.
Nicholas Kynnersley, a servant, writes to Bess (countess of Shrewsbury) with report of a lackey from Sheffield coming late at night to ask after Bess's whereabouts. He suspects the reason is 'to bring my lord [Bess's then estranged husband George, sixth earl of Shrewsbury] word of your absence here 'so that he may come uppon the sudden and find you away'. Arbella (Stuart), Bess's grand-daughter, eats well but has not been to school for six days.
Nicholas Kynnersley, a servant, sends Bess (countess of Shrewsbury) part of her 'principal jewels' from Wingfield. He assures her that all things are in as good an order as when she left, that security measures are in place and that she has authority.
Robert Devereux, second earl of Essex, writes to Bess (dowager countess of Shrewsbury) to recommendation the bearer, Christopher Hannam, who wishes to enter Bess's service as a gentleman usher. Despite the endorsements by Essex, Sir John Wingfield and Lady Kent, Hannam does not subsequently appear in the account books or wage lists for Bess's households.
Susan Wingfield writes to Bess (dowager countess of Shrewsbury) informing her that her search for a clerk for Bess has yet been unsuccessful; but recommends the bearer of the letter as a porter. Apologises for employing a scribe for writing the letter, but 'my finger continues so evil as that I am not able to hold a pen'.
Bess (dowager countess of Shrewsbury) writes to Richard Bagot regarding a workman named Tuft who has 'dealt very badly and lewdly with me'.
Roger Manners, fifth earl of Rutland, writes to Bess (dowager countess of Shrewsbury) on behalf of the bearer of the letter, expressing the latter's thanks for her favour and eagerness to be of service to her. Manners also acknowledges gratitude for Bess's favour shown towards himself, 'and the more that no sinister practice can withdraw your good opinion from me'.
Sir John Stanhope and Sir Robert Cecil write to Bess (dowager countess of Shrewsbury) by commandment of the queen, regarding Bess's granddaughter Arbella Stuart - namely to do with how 'some base companions (thinking it pleasing to her youth and sex) to be sought in marriage, were content to abuse her with a device that the earl of Hertford had a purpose to match his grandchild with her'. They assure her that Hertford had no such intention and request Bess to assign some members of her household to keep a close, however discreet, watch over Arbella. As for Bess's request to be 'freed of her', the queen can think of no other fit place for Arbella.