@Karla616 are they asking for a discount? Some things to consider:
What is the purpose of their gathering and the ages of the group? You don't want to discount only to be left with an even bigger cleaning job than normal.
Would you likely rent all 4 cabins anyway?
Is having all 4 cabins occupied less work for you, or more?
How long is the stay? I don't do any discounts anymore but I only have one place. A longer stay discount to me doesn't work, there is much more wear and tear. I love the weekenders!
Often the guest asking for a discount is the one you want to avoid because they will feel entitled to other perks as well.