Why did this girl act like this?

After months of being abrasive to her,and her to me(we're just acquiantances)i finally had a good conversation ,wherre i was able to put the focus on her ask how her year was going,how she was,tell her the good stuff about what she's done how hard she's worked and things of tht nature,i even restrained my temper and refused to loser it in front of her,and respectfully patted her seat(the back of it)and gave her the space she needed.Shortly thereafter,she walked by me looking warm peaceful and with a bit of a smile on her face,and had a friendlier disposition towards me than previous.Is this a good thing?And what does it mean?