If a woman re-marries & consumates the marriage. Does the woman’s daughter become Mahrem to her now-husband? Can the woman’s daughter be without hijab in front of her mothers husband, etc.

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Yes according to this ayat of Quran

Your stepdaughters under your guardianship if you have consummated marriage with their mothers—but if you have not, then you can marry them

Quran 4:23