"Is she her grandmother?"

Translation: Är hon hennes mormor?

[Delstein]

Not a case where you want to confuse "hennes" and "sin".

[stockholmer]

why isn't it sin? doesn't hennes mean hers?

[Zzzzz...]

I think if one would use sin here, the sentence would mean that she is both the grandchild and the grandmother, that is, that she is married to her own grandfather.

[stockholmer]

oh that would be...wrong

[jxxmxxj]

See also: https://en.wikipedia.org/wiki/I%27m_My_Own_Grandpa

[Carlutch]

And she would be also her own grandmother

[Imjac]

'sin' is only used if the person refered to is also the one doing the action.

[GabyPramo]

How can I tell if it is mormor or farmor?

[ThomasRo2]

You can either ask or look at the family tree or watch for similarities to the mother or the father :-)

[AnthonySvenska]

Is there a generic term for grandmother that could mean either maternal or paternal side?

[sotnosen93]

No. There is a generic term for which gender the person themselves is (morförälder = mother's parent, farförälder = father's parent), but not for which side of the family they come from.

[CaptainIkag]

Why does morfar not work?

[Yerrick]

The second word defines who it is; the first is whose it is. So you're talking about the maternal grandfather in your question, not the paternal grandmother.

[CaptainIkag]

Oops I see now, I mixed up the order

[dan.rumpz]

It's counting "mormar" as a typo but doesn't it technically mean the same thing, just her mother's grandma instead of her father's?

[Zmrzlina]

Mormar is a typo. But mormor and farmor aren't. ;)

[iBrow.]

It's a typo; maternal grandmother is mormor and paternal grandmother is farmor.

[layne712526]

Why doesn't the V2 rule apply here? IOW, why is "Hon är hennes mormor?" incorrect?

[KiwiDressager]

Because this is a question so the V2 rule does not apply. A question either begins with a question word (när, varför, hur, vad, vem...) or a verb. Much the same as in English where we flip the subject and the verb.

Your sentence “Hon är hennes mormor” is a statement: “She is her grandmother”