Is the second husband of the mother forbidden to her granddaughter, and what are the conditions for that?

If a man marries a woman and consummates the marriage with her, her daughter and the daughters of her sons, and their descendants however far removed, become forbidden to him, based on the Almighty's saying: "And your stepdaughters who are under your guardianship, [born] of your women unto whom you have gone in." The wife's granddaughter is considered among the stepdaughters, therefore the grandmother's husband is a mahram (definition) to her granddaughter. It is permissible for a woman to unveil before her mahrams what is commonly apparent of her, provided there is no fear of fitna (temptation) or suspicion.