I showed our new house to my mother
Did this answer not get accepted? It should. It's true that "mama" is better translated as "mum/mom/mam" than "mother" but it is the same thing in practise and shouldn't be marked wrong.
Added such a word order now.
The audio here has a female voice, which doesn't match with "Pokazałem"
It's still a new feature that we can ensure the right voice, we haven't finished going through the whole course with the tags. I just tagged this sentence as 'male', so soon only the male voice will read it.
Should house be accepted or is that a completely different word?
It's the same word in Polish and I guess it would feel more natural as the main English answer, because what you show is rather the building. Changed now.