My aunt lives somewhere on the territory of European Union and I navigated to her house in street view mode on Google Maps. I noticed that by navigating those images you can see into her house!
In Germany, taking pictures - and publishing them - is legal, if they're taken from public areas, from the general perspective of a passer-by, and if the picture doesn't make individual persons recognizable.
(There are some restrictions about making persons recognizable; if you take a picture of a monument or other building that would typically be photographed by tourists, and if the topic of the picture is clearly the monument, not a random bystander, then it's OK to publish even if the bystander's face is visible. But that doesn't work for individual's houses).
Still, Street View got into trouble because their cameras are mounted on roofs of a car, in a height of 2.5-3 meters, so they violated the "perspective of a passer-by" rule. To return to the example of "bathroom", the camera could well be able to see you nude when a passer-by would only be able to see a small portion of the ceiling next to the window.
Because of this, and because many Germans were uneasy with seeing their houses on the internet, as a condition to permit Street View at all, the German government insisted on allowing people to request their house to be removed; in 2010, approximately 250000 people made use of that (source: https://www.bbc.com/news/technology-11595495).
Because of the high resistance against Street View in Germany, Google published what they had in 2011, but stopped collecting more images. This is explained in https://bigthink.com/strange-maps/germany-street-view/, which also explains some of the reasons why Germans are so heavily biased for privacy.
Dale M's answer is correct, but there's more:
what if she had a bathroom on that window and you could see her bathing?
That could well lead to her being charged with public nudity / indecent exposure (depending on where exactly in Europe it is).
The fact that she would be exposing herself inside her house wouldn't matter: the fact that the public could easily see her from the street would. She would be aware of the visibility, and not taking steps to prevent it (e.g. privacy curtains) could well throw her into legal trouble.