HOA insists my sister and I are not a single-family household and one of us should move out. We’ve lived here all our lives.

If included partners, children, grandchildren, parents, grandparents, step parents, step children, uncles, aunts, nieces, nephews, children of uncles and aunts, children of nieces and nephews, BUT NO SIBLINGS. It even had a clause that said co-owners are not allowed to live there unless they are a single family based on the definition. We also received a letter from them telling us of our violation and demanding us to comply.