Your search for "Bess as daughter and sister: letters from the Hardwick family" returned 6 letters.
James Hardwick writes to his sister, Bess (Lady St. Loe), a second time ('eftsones') concerning a mix-up in their letters; a recognisance; and his various ailments (haemorrhoids, headache and the effects of age). The postscript reports the marriage between Francis Willoughby (1546/7-96) and Elizabeth Littleton (d. 1595).
Elizabeth Leake asks her daughter, Bess (Lady St. Loe), to lend her son (Bess's brother, James Hardwick) money for the acquisition of land and thanks Bess for kindness shown towards her half-sister, Margaret (née Leche).
James Hardwick writes to his sister, Bess (Lady St. Loe), excusing himself for not coming to see her in person due to a painful 'cough of the lungs'; and asks her for money, offering to pay it back with interest.
Elizabeth Wingfield writes to her half-sister, Bess (countess of Shrewsbury), to confirm that her husband (Anthony Wingfield) has delivered Bess's venison to the queen and spoke with her for 'a long hour', during which time the queen expressed her 'love and affection' for Bess and her husband George, sixth earl of Shrewsbury. The queen is looking forward to seeing Bess. On the overleaf, in Bess's hand, there is a list of noblewomen and noblemen.
Elizabeth Wingfield writes to her half-sister, Bess (countess of Shrewsbury), describing how well the queen liked the garments sent by Bess and her husband George, sixth earl of Shrewsbury, and how it 'has caused her to give out such good speeches of my lord and your ladyship as I never heard of'. A postscript reports that all are well at Hackney.
Elizabeth Wingfield writes to her half-sister, Bess (countess of Shrewsbury), that she has consulted with Lady Frances Cobham (lady of the bedchamber to Elizabeth I), who does not advise 'giving money' (presumably as a gift to the queen). Bess's grand-daughter, Arbella Stuart, is well and a tailor has been sent for to make her a new green velvet gown. Lady Cheke has 'had long talk with her Majesty lately of my Lord's [i.e. Bess's husband, George's] hard dealing and the queen gave many good words what she would do for your honour'.