Hey Yoda...I'm no electrician but I don't believe that your house would need to be completely rewired with copper. A good electrician or competent trusted handyman (if there are no permits required) can attach copper pigtails between the aluminum wiring and all outlets, light switches etc. Relatively expensive but not nearly as expensive as a total rewiring of your house.
Your neighbor might just be a good neighbor. And if she needs to borrow your tiller it's a bargain for both of you. If you don't trust her you could put all drugs and valuables in a safe place where she won't have access.
If I had a neighbor with a tiller I might offer that kind of deal myself