This is a great question! In this scene Ophelia is bombarded with the opinions of both her brother and her father in regards to her relationship with Hamlet. Her brother is warning to protect her virtue and her heart because no matter how Hamlet feels about her, he is a prince, and princes don't usually get to marry whom they want or whom they love. They marry for political gain and for the good of the state. Polonius is even more harsh. He belittles Ophelia and Hamlet's feelings for each other and suggests that Hamlet is only using her for whatever he can get. Ophelia tries to defend him and their relationship, but Polonius cuts it down to "springes to catch woodcocks! I do know, when the blood burns, how prodigal the soul lends the tongue vows." He is suggesting that Hamlet will say whatever he needs to in order to "have his way" with Opehlia.
If I were going to interview Opehila I would ask her about how she feels about Hamlet, and I would let her answer at length, not just cut her off like Polonius does. I would ask her what she speicfically means when she says that Hamlet has given her "many tenders of his affection." What are tenders? Give examples. I would ask what she means by saying the Hamlet has "given countenance to his speech with almost all the holy vows of heaven." What exactly has he said? How did he say it? What does she mean by almost all the holy vows. I think I would probably ask her, point blank, if she and Hamlet are having a sexual relationship. I would also ask her how she feels being spoken to this way by Laertes and Polonius. Does she see their points? Is she hurt? Will this affect her feelings for Hamlet?
There are so many neat things to consider about specific things that are said to her that you could ask her about. Have fun thinking about what Opehlia might like to say in order to clear the air a bit more!