De Beauvoir is a controversial figure. She undoubtedly had a major influence on feminism but it is also firmly established that she abused her position as a teacher and a famous writer to groom some of her teenage students into sexual relationships with her before tossing them to her boyfriend.
Geez, I knew that France has had a...different relationship with age of consent laws, but I didn't know so many of their "great thinkers" were against the idea completely [1].
She's also controversial (to say the least) for her smear campaign against Albert Camus, who didn't publicly endorse hers and her boyfriend Sartre's pro-Soviet politics.