
A workaround for this is to let Piper kill her.
During the quest In Sheep's Clothing, Geneva may become hostile when the player attempts to fight Mayor McDonough. If you could send settlers there, it would cause problems indefinitely because the required stuff for happiness can't be built. Or rather, it's a highly modified settlement with no food or water or defenses. If you buy the house before asking for work, the option that adds the quest to check out the wanted posters, will no longer be available as no further conversation with Geneva is possible after that point. Because they use the same menu as settlers to get sent places, and home plate isn't a settlement. If Geneva is killed before the key to Home Plate is obtained from her, there is no way to obtain the key or access to Home Plate.
After completing In Sheep's Clothing, Geneva somberly reveals that she was aware of the rumors circulating about her and McDonough, but claims he was just as much a mystery to her as to anyone, and that she had a poor opinion of his temper.
During Getting a Clue, Piper and Geneva have a discussion where Piper makes a comment on Mayor McDonough and Geneva having an affair.