OMG... That's so creepy.......ㅠㅜ

My place is unit 1, so there are no other units to the left of it. Then, this elderly lady wearing a pink hat (like in the third image) knocked hard on my door a couple of times. When there was no response, she just stood there staring intently at my door, you know? Glancing over... I thought it was the delivery guy bringing the 500ml sparkling water I ordered last night...ㅠㅜ But then I heard a noise and looked towards the side door, and she turned away as if she hadn't been looking. I was so startled that I quickly wrapped myself in a blanket in the living room. After confirming that the lady, with her hunched back, had left after our eyes met, I looked out the front door and realized there was no delivery...ㅠㅜ I had the side door open a bit for ventilation, but seeing it open, should I assume she was curious about what goes on in this house?ㅠ Regardless of gender or age, isn't staring into someone else's home a crime?ㅠ Wow... I guess I can't even ventilate my house anymore...ㅠㅜ What's with people these days?ㅠㅜ It's scary...ㅠㅜ