If you can't love your little neighbour, if you can't show any love to your little neighbour you are already beginning to destroy his or her sense of trust in other human beings.
Alternatively, she could direct in the will that her share of the house is held in a trust, and that you have a right to occupy so that the others cannot force a sale - albeit they will ultimately receive a share of the proceeds should it be sold.
Her mother, who runs a support group for parents of allergic children, recommends finding a doctor youtrust, who makes you feel comfortable and who is knowledgeable about allergies.