Did I miss her hints? Need advice on a strange interaction with my sister's friend

I [23M] need advice regarding an incident with my sister's friend [23F] whom I've known for about 2 years.

I want to share an incident that happened recently and get your opinion on it.

My sister has a friend who is my age. She often comes to our house to hang out with my sister. Her family is very strict and typical Indian, so they don't let her go anywhere alone. However, her family knows our family very well.

Recently, my entire family went to our hometown, so I was staying at home completely alone. She knew about this. I work and so does she, so Sunday was a holiday for both of us. It was raining heavily on Sunday, and we had no electricity since Saturday. However, my house has an inverter (power backup), which she was aware of.

Around 10 AM, someone knocked on my door. I wasn't expecting her, but when I opened it, she was standing there. She very politely asked if she could charge her phone at my place since her battery was dead. I said okay, plugged her phone in, and she left. I went back to doing my work.

At around 1 PM, there was another knock on the door. I opened it and saw her standing there again. She asked if her phone was charged. I checked and saw it was above 50%. She had recently bought a new Google phone, so while she was standing at the door, I casually asked her about it. She smiled and said yes. Just as a polite gesture, I asked her, "Do you want to come in and sit for a while?"

I honestly didn't think she would agree because of her strict family and because she knew I was alone at home. But she came inside without any issue or making any excuses.

After she came in:

I asked her if I should close the door, and she said, "Yes, close it." (The windows were already closed because of the rain).

She sat on the sofa. Since it was a single-seater sofa, I sat right next to her on a chair.

We started talking and catching up. While I was making some jokes, she hit my shoulder with her hand while laughing.

When I asked to see her new phone, she handed it to me, and while doing so, I felt she was being a bit touchy.

Later, when she was getting ready to leave, her charger was in the board near my chair. She came and stood directly in front of me, very close. When she handed me the charger, our hands touched. She stayed standing close to me.

At that point, I felt something and said to her, "I want to tell you something."

She said, "Say."

I said, "Forget it, I'll tell you tomorrow."

She said, "No, tell me now."

I replied, "No, it's fine, I'll tell you tomorrow."

She stood there waiting for about 2 minutes while I got on my mobile phone. Suddenly, she seemed to get annoyed/angry. She said, "I am leaving," and left, closing the door behind her. I felt a bit weirded out by her sudden shift in mood.

Now, two days later, my family has returned. Whenever she comes over to meet my sister, she acts strange and ignores me.

Did I miss her hints that day, or why did she get annoyed and start ignoring me?

Note: This is not a fake story or made-up scenario. I honestly couldn't believe she came inside. As far as I know, any other girl in her position—or even her—would typically just take her phone and leave from the door, especially considering how strict her family is and how her sisters might get suspicious if they saw her. Yet, she came in without hesitating.