Why is she staring and getting her friends to follow me?

Talked with this girl for around 3-4 weeks but she eventually stopped talking. No biggie I moved on with life.

I met her again recently on a night out and she seemed really shocked to see me. I tried talking to her but she seemed reserved so I left her alone. Her two friends later followed me on Instagram that night.

I met her again the next night out and she just seemed really surprised again. I was going to talk to her but my female friends interrupted at that moment and told me to go downstairs (my friends were there).

As I walked off to the stairs, I noticed she just froze in the same spot and had just watched the conversation without saying anything. She was still staring at me, not even walking or looking away.

Why did she seem so bothered?
Why is she staring and getting her friends to follow me?
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