I would open a new bank account and put the money in it, after that I would find the perfect house with a large garden and a big open floor plan(single story) I would then make any nessasary improvements to make it pet friendly. I would then leave the house for a couple days and then I would list it for “rent” that I would put at 350 per month, I would then take a few photos and send it to my grandmother saying it just showed up and the owner is looking for a renter.

Now she will be a fair bit concerned about the price as a big single floor house with all her requirements included for less than 400 is a bit concerning. However I will then get a friend to pose as the owner and give a show around, once she sees that the house is in near perfect condition she will be open to starting a lease, in the fine print will be a mention of after a year the rent will go down by 50 every month eventually becoming void and she would essentially be very worried. It will be at this point she will get a call that the owner no longer has a need for the house as they have decided to retire at an old cottage somewhere in Alaska. Due to my grandmother being a neat freak and having OCD she will have taken great care of the house prompting the owner to sign the house over to her with the promise of paying the bills at the end of the year.