I was awake until about 10 past 12 last night to find my previously mentioned answers.

I never went downstairs as my parents were watching TV 'till 1 in the morning but at one point i heard footsteps walking to the storage room.

In fact, they were going up and down the stairs a lot between 11:30 and 12:00.

Conclusion: Not enough evidence to say.

I also spent a lot of time talking to an online friend on discord about guns, shooter games and the combination of mini skirts and thigh high socks. Time well spent in my opinion.