Why is lady furnival afraid that Lord Douglas will find out about crispin?

Lady Furnival is afraid that Lord Douglas will discover Crispin's true identity because it could jeopardize her family's reputation and safety. Crispin, being the illegitimate son of Lord Furnival, poses a risk to the family's social standing, and any revelation could lead to scandal or political repercussions. Additionally, she fears for Crispin's life, as Lord Douglas may see him as a threat or a rival. This fear drives her to protect both her son and her family's interests.