Salaam aleikum wa rahmatullah wa barakhatu. I have a question, my wife and I know a very pious sister who is advanced in age...57 whom is unmarried. Her family she lives with who are non-Muslim is hostile towards Islam and desire her to leave. I offered her to come under my protection if she has to make hijrah as she has little to no means and has no where else to go. My question is that is it halal for her to stay with us under my protection or must I take her as a second wife? I have the means to by the way. My wife and I have discussed this even though the possibility of me taking a second wife hurts her feelings she gives her consent and will not do a khula if such a thing were to happen as this would be a necessity. They love eachother as sisters. My wife is blind and crippled so of course it would be a great help if she were to be under my protection. I am not entirely sure on the best way to go about it if she is forced to make hijrah. My intentions are only pure and honorable as I have no lustful desire. Jazak Allah Khair.