The major conflict and resolution of the play involve

Conflict- A scenario in which a character faces a problem in the story that needs to be resolved. Resolution- And in which there would be a way to resolve this problem on some type of way.

Explanation:

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."