Isn’t that step-sister-in-law? (Presumably, no proof they ever got married yet, by any custom)
Technically, yes, it would be step-sister-in-law, but that seems like it is splitting hairs. Kin is kin, even by marriage. Henry and Cinderella did get married. In 7×1, Lucy declares to Henry, “I’m your daughter, and my mom is your wife and your true love!”
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"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy