Question

Which sentence below uses a pronoun in correctly?

she and he will be making sure that the car is clean.
The spelling bee winner was she.
him and 1found the buried chest in the backyard.

Answer 1

Two of the sentences use incorrect pronouns, actually. You are using the wrong ones, they should instead be as follows.

The spelling bee winner was her.

He and I found the buried chest in the backyard.