The paintings are set as if they were jewels. One is meant to be Lord Dillon, brother of the 12th Viscount Dillon.
Lord Dillon was Catholic and was therefore barred from serving in the English army and so decided to serve in the French army instead. Something went seriously wrong and he died not on the battlefield but by the guillotine.
The identity of the lady in the second picture is unknown, but she was not Lady Dillon.
The contributor found these miniatures in her mother's wardrobe after her death.