Why did she blocked me after acceptig my friend resquest and responding to my girst message?

I added her a year ago on facebook and she accepted me , i didn't talk to her

Two days ago i saw her in the train station , i remembred that i had her on my fb , i sent a message on messenger in the night "hello" , she answered me this morning with "hello" , this evening after finished my work , i texted to her how are you? Two hours later i found out that saw the message and blocked me 😅

Can i you what was turning in her mind? ps: i don t know her and she doesn't me real life , and i I've had situations like that where i added girls i dont know then when be meet each other in real life

Updates
1 y
The conversation was :
Me: hello
Her : hello
Me: how are you?
Her : seen and block
Why did she blocked me after acceptig my friend resquest and responding to my girst message?
Post Opinion