By the way, is it obvious in this sentence that the house belongs to the mother or could the owner of the house also be some other 'she'? Is there any other way than context to tell the difference? In my native language Finnish there would be different forms for these meanings.
Thank you but actually that's not quite what I meant. Obviously the owner is specified in this sentence but does 'haar' necessarily have to refer to the subject of the clause (the mother) or could it possibly refer to some other female character relevant to the context? For example if a grandmother was mentioned in an earlier sentence could it also be her house that we're talking about?
I understand the sentence and it's most likely interpretation here. I'm just speculating because I'm interested in the structures of different languages that make different specifications and leave different things to depend on the context. :)
It may confuse more but I try to open up how it's done in Finnish:
Äitini menee taloonsa. = My mother goes into her house. (her own house)
Äitini menee hänen taloonsa. = My mother goes into her house. (someone else's house)
So if we want to specify that it's the mother's own house, we only use the possessive suffix -nsa and add it to the noun talo 'house'.
But if the house belongs to some other person we still have to use the possessive suffix -nsa to mark third person but also add the possessive pronoun 'hänen'.
So in both situations it's "her house" but in the first she = mother, in the second she = someone else known in the context. (And actually, the someone else may also be a man because there's only one personal pronoun for third person with no gender specified – that's an ambiguity our language can stand. :) )