DVC discount for Adventures by Disney

[rnorwo1]

Hi All,
I was wondering about the DVC "discount"/lowest fare guarantee for an Adventures by Disney trip if anyone has used it. I was planning a trip for us, my MIL, and SIL, but now my family and I are not able to go. Can I still book it for them to get the lowest rate with our DVC membership, or would I have to be one of the travelers to get it?

Thanks for any info; I had a hard time getting through to them to ask directly.