This paragraph is mainly about how Van Lew prepared the Union soldiers to return to their army.
Van Lew’s home was a safe house for escaped Union soldiers.
Van Lew obtained information from escaped Union soldiers.
Van Lew’s mother and servants were part of her secret operation.

the pronoun reference replaces a noun, but you have to make sure there's no room for confusion.

in the first sentence "her" could be referring to shely or to the sister. the answer there is "shelly called her sister and told her about the new baby."

in the second sentence "it" could be referring to the roof or the floor. the answer there is "since the roof leaks on the family room floor, we need to repair the roof."

noun phrase/ noun phrase/ verb phrase/ noun clause/ awnsers are in order to questions above

the answer to the problem is most likely a