During the Exclusion Crisis, a Protestant faction wanted to make her son heir to the throne, fuelled by the rumour that the king might have married Lucy, a claim which he denied.

[citation needed] In 1647, when Walter was 17, after a long legal battle between her parents, the House of Lords ordered her and her brothers to live with their father, as their mother could no longer afford to keep them.

[1] Walter then sailed to the Dutch Republic, either alone or with her uncle, to join the exiled court of Charles, Prince of Wales in The Hague, hoping to find a lover among the many young aristocrats there.

[1] In May 1648, Walter managed to meet and charm Prince Charles, who had by then been living in France but visited The Hague for a short time.

On 9 April 1649, Walter gave birth to a son, James (1649–1685), who was acknowledged by Prince Charles as his illegitimate child.

In early 1656, when she was in Cologne, some of the king's friends persuaded her to return to England by giving her cash and a pearl necklace and promising her a yearly allowance of £400.

By this time, Lord Thomas had left her and she had no money to feed her children, as King Charles was unable to pay her allowance.

The king, wanting custody of their eight-year-old son, attempted to kidnap him in December 1657, and succeeded at capturing him in March 1658.

She made a General Confession of her life to John Cosin, future Bishop of Durham, insisting that she had married King Charles.

[citation needed] Walter died between 29 August and December 1658 and was probably buried in the Huguenot cemetery in the Faubourg Saint-German district of Paris.

[citation needed] The marriage of King Charles and Catherine of Braganza (1638–1705) did not produce legitimate children, leaving his brother, James, Duke of York (1633–1701) as heir to the throne.