In this section, “family assistance dwelling” means a house, and the lot or curtilage on which the house is erected, if the house: is not a vacation home; is not the residence of the homeowner but treated as used by the homeowner for personal purposes within the meaning of § 280A(d) of the Internal Revenue Code; and is the only residence of an individual who: is the brother, sister, half–brother, half–sister, spouse, parent, step–parent, grandparent, child, step–child, adopted child, or grandchild of the homeowner; makes rental payments to the homeowner that are less than 90% of a fair rental price paid for a similar dwelling in the same area; and is entitled to low income assistance benefits under a federal or State program. The Mayor and City Council of Baltimore City or the governing body of a county or of a municipal corporation may grant, by law, a tax credit against the county or municipal corporation property tax imposed on a family assistance dwelling. The Mayor and City Council of Baltimore City or the governing body of a county or of a municipal corporation may provide, by law, for: the amount and duration of the tax credit under this section; additional eligibility criteria for the tax credit under this section; regulations and procedures for the application and uniform processing of requests for the tax credit; and any other provision necessary to carry out the credit under this section.