It appears to me that she was being polite and simply asked a question. People can ask questions, whether you deem them stupid or not. I teach social skills to bright/intelligent high school students on the spectrum. The scenario you described sounds similar to one's I have witnessed with my students' interactions. They have great difficulty taking the perspective of others. They tend to use logic that comes across as rude. I teach them that in social communication these are not the best ways to interact.

Some people are sensitive to sounds people make: breathing, chewing, drinking, etc. It is called misophonia. Perhaps, this was such a person; and, knowing that many people who are bothered will not say anything, she just wanted to make sure the noises she was making were not bothering you?

I never miss people ... with public venues being the worst. People, in order to feel secure, need to have everything appear as they think it should be, generally based on a move or shit-com. Police take that concept to another level.. If one behaves as an individual, or fails to adequately acknowledge their presence, these people feel it’s within their right to pull you into their (often fucked up) world. It gets old - fast.

I suspect crap like that is partially responsible for the ‘earbud evasion.’ It’s not that most are listening to something they feel compelled to ‘hear,’ but it gives them a visible excuse to ignore the annoying masses.. I’ll often use earplugs, then give a stupid smile to a stupid question

It sounds like she was either trying to start a conversation or, more likely, thought that she may have genuinely offended you in some way.

The fact that you were reading a rabbinic parable "in order to understand the world a bit more" tells me everything I need to know. Jesus...

Making small talk and afraid of offending

sorry, but there are people who are embarrassed, or ashamed to tell people that they are suffering discomfort at their actions. Sometimes people will just give looks or make gestures. Sometimes as in maybe this case, the person just wants attention which they probably wanted by making noise like sucking through a straw at the end of the drink which will make noise. There have been many times when people were causing a disturbance to me in a library and I didn't voice my displeasure hoping the library staff would do something about it. Unfortunately, these days apparently there is no decorum required in libraries anymore, at least at my library.

Perhaps she was just being polite ... an answer of “no, not at all” may have been a more appropriate response from you,

I think you did not quite get it. Seems to me that she wanted to talk to you and that was an opening for her.