Thank you for writing, and we're sure that Lisa would have enjoyed discussing this question with you, but unfortunately we don't have a current email address for her.
From our standpoint, her discussion of Eden before the Fall represents the ideal, or the will of God for this earth, and this is the same, or very similar to what we know about heaven.
What she wrote about was living in the will rather than the concession of God that were granted to fallen human beings, because of their lack of obedience, in the hope of bringing them back to Him.
Jesus pointed us back to kingdom living, which is living in the heavenly will of God. In the Beatitudes He taught us that God's blessings come from our compassionate living, which would preclude doing the horrible things that are done to animals in factory farms and slaughterhouses. In verse 9 He tells us the children of God are the peacemakers, which Paul seem to pick up on in Romans 8:18f where he speaks about these children of God freeing the whole of creation form its present suffering and corruption, which includes the animals.
In Matthew 5:48 Jesus commands us to be perfect as our Father in heaven is perfect, and in Matthew 6:10 He tells us to pray for our Father's heavenly will to be done on earth as it is in heaven. Since there is no pain, suffering, or death heaven, there can be no killing or exploitation of animals. So, if we pray as Jesus taught us, then we should also do everything in our power to end the pain, suffering and death of the animals here on earth.
We hope this answers you question. It could also be a very interesting discussion for your students.
In the Love of the Lord,
Frank and Mary