Why does she say “a bathroom“ instead of “the bathroom“? Does the room has two or more bathrooms?
Native speaker’s answer
Rebecca
Here she most likely uses 'a bathroom' instead of 'the bathroom' because she has multiple bathrooms in her house and hasn't decided which one to go to yet. If there was only one bathroom to choose from or if she already knew which bathroom she was going to go to, she would have said 'the bathroom'.