Charlotte de la Trémoille was French, a Huguenot, born at the Château de Thouars in Poitou in approximately 1607. Her mother was Charlotte Brabantine of Orange-Nassau, and her maternal grandfather was William the Silent, Prince of Orange, who led the Dutch Revolt against Spain and whose assassination at Delft in 1584 made him the first head of state to be killed by a handgun. Charlotte married James Stanley, Lord Strange, on 26 June 1626 at The Hague, in a palace of the Prince of Orange, in the presence of the King and Queen of Bohemia. Her dowry was £24,000. They had several children, of whom six survived to adulthood: Charles (later 8th Earl of Derby), Henriette Mary, Katherine, Amelia, Edward and William. Three sons and three daughters accompanied Charlotte to the Isle of Man in July 1644.

When the Royalist position in Lancashire began to collapse in late 1643, Charlotte held Lathom House with a garrison under six captains commanded by Major Farmer, under direct commission from her husband. When Parliamentary commissioners demanded the house's surrender in February 1644, Charlotte told them she was under a double trust, of faith to her husband and of allegiance to her sovereign. She asked for a month to consider their terms. When they refused, she told them she hoped they would excuse her if she preserved her honour and obedience, though in her own ruin. The first siege lasted four months. Charlotte was outside the gates during the fighting, near the trenches, visible to both sides every time the garrison sallied out. The Parliamentary forces lost approximately 2,000 men during the siege; the garrison lost approximately 400. The siege was raised on 27 May 1644 when Rigby retreated before Prince Rupert's advance into Lancashire.

Charlotte arrived on the Isle of Man on 30 July 1644 with her three sons and three daughters. Castle Rushen became her home, and for the next seven years she governed the Island in her husband's name while the war on the mainland ground through its final stages. Her own letters from the Island, preserved in the Trémoille family archives and published by Mme de Witt from originals Charlotte wrote in French to her sister-in-law, are the only source that gives Charlotte's own voice during these years. In late 1649 she nearly died, describing seven weeks without sleep and barely any food. During 1648 and 1649, from Castle Rushen, she was also engaged in a detailed correspondence about the tabouret - the right to sit on a stool in the presence of royalty at the French court - on behalf of her niece.

On 6 August 1651, Stanley signed a formal commission giving Charlotte authority to govern the Island in his absence before sailing for the mainland. When the Earl was captured and executed, and William Christian's rising surrendered the Island to Parliamentary forces under Colonel Duckenfield in November 1651, Charlotte held Peel Castle on St Patrick's Isle. She negotiated her own terms with Duckenfield separately from Christian's surrender of the country, securing safe passage for herself, her children, and her household. The two negotiations were independent.

After the wars, Charlotte compounded with the Parliamentary authorities and lived at Knowsley. At the Restoration, her son Charles, 8th Earl of Derby, moved against William Christian. The indictment named treason not against the King, not against the Crown, but against the Countess Dowager of Derby - the authority she had exercised under commission from her husband during the siege. Whether Charlotte desired the prosecution, merely permitted it, or was used by her son as a legal instrument, the record does not say.

Charlotte died at Knowsley in March 1664 and was buried beside her husband at Ormskirk on 6 April. The burial register recorded her passing with two Latin words: "Post Funera Virtus" - virtue after death.