Problem: Joan made sure to thank Susan for all the help *she* had given.

Do "she" and "Joan" mean the same thing?

Answer: no

Problem: Many people start to read Paul's books and can't put them down. *They* are gripped because Paul writes so well.

Do "They" and "Paul's books" mean the same thing?

Answer: no

Problem: Anna did a lot worse than her good friend Lucy on the test because *she* had studied so hard.

Do "she" and "Lucy" mean the same thing?

Answer:
yes