There are so many examples of strong female leads in King's novels - ones with power, excellent morals, and the ability to find their way out of whatever situation they've found themselves trapped in. In Gerald's Game, Jessie Burlingame uses her past trauma to escape from her chained position - finally moving from victimized to triumphant. She beats all those who abused her in her life to start again, both physically and mentally. Rosie McClendon in Rose Madder fights to escape from her abusive ex, utilizing a painting. Beverly Marsh defies all odds in It, fighting for her place in the world despite all that she is experiencing. These are strong characters that can be looked up to, admired. The battle through circumstances with strength and willpower like no other. There is no sign of sexism in empowerment.
Simply placing women in lead roles is not enough to determine whether the novels are sexist or not. It's the treatment and portrayal of women, and within that lies the issue with Stephen King's books.
[P1] King creates admirable female leads. [P2] They empower rather than put down women.
Rejecting the premises
[Rejecting P1] The issue is not the women's personalities, but how they are treated in the novel.