Chloe is non-threatening to other women. Women know that Chloe isn't competition for them - in looks or for men's attention. And none of the men in the house were attracted to Chloe, not including Jack
Female voters are known for voting out women early.
It's also a "white" house - people of colour are also usually voted out early.
If you want to know the voting demographic, look at who is in the house - young white males. Voted for by young white females.
The only reason why Helen stayed until the end last year was because she was awarded a pass to the final. But I can't explain how Helen won