Translation:That is hers.
Still wrong August 2018.
Especially frustrating after being taught 私の物 is "my stuff" but 彼女の物 is not "her stuff", which makes the most sense.
No that would be あのもの, grammatically this sentence is saying 'That is her thing'.
I almost want to argue that "That is her stuff" is more right than "that's hers" because "mono" translates to stuff.. maybe I'm not understanding some nuance?
Couldn't you just say あれは彼女のです ? What's the significance of adding 物 ? Is this just a more formal way of saying it?
I think it could be (should be). Also:
Those are my girlfriend's
Those are my girlfriend's things