Take the to Maybell Maclure.
Quest Text Edit
Take this invisibility liquor to young Maybell. It should last long enough for her to visit Tommy Joe.
Did you deliver my letter to Tommy Joe? What did he say??
Oh...my! I feel guilty deceiving my family, but my feelings for Tommy Joe are too strong to ignore.
Thank you, <name>. I'll drink this liquor as soon as I have the chance and sneak away to my love.
And for you... please take this.
After the potion is drank she becomes invisible.