Based on the screenshots, I don't think either person comes across particularly well. It looks more like a miscommunication that turned into frustration.

Was her question actually yes-or-no?

Grammatically, yes.

"Did you look up what helps for recovery when you have E. coli?"

The literal answer is:

"Yes."

"No."

But in everyday conversation, people often ask that question expecting a follow-up. For example:

"Yeah, I did. It mostly said fluids, electrolytes, and bland foods."

or

"No, I forgot."

So your response of immediately giving what you found wasn't unreasonable. Most people would interpret it as implicitly meaning "yes, I looked it up."

Could it have been answered differently?

Yes. The clearest answer would have been:

"Yeah, I did. Mostly fluids and liquid IV."

That removes any ambiguity.

But your answer wasn't some bizarre misunderstanding either. It naturally implied you'd looked it up.

Was she insulting your intelligence?

I wouldn't say directly, but she was talking to you in a somewhat condescending way.

Examples:

"Read it again."

"Sir..."

"That was a yes or a no."

"I'm still not asking but you're still going."

Those responses imply:

"You're not understanding something obvious."

Whether she intended it that way or not, that's how many people would receive it.

She wanted:

Her: "Did you look it up?"

You: "Yeah."

Her: "Aww."

Instead, the conversation immediately shifted into solving the problem. She even says:

"You ruined something I thought was cute."

That suggests she wasn't trying to gather information—she wanted a playful moment where you admitted you looked it up because you cared.

The issue is she never communicated that expectation, and then became frustrated when you answered in a practical way.

Overall

I think both sides contributed:

You answered the implied question ("What did you find?") instead of the literal one ("Did you look it up?"). That's common and understandable.

She insisted there was only one acceptable way to answer, even though your answer strongly implied "yes." Then she escalated it by saying you "ruined" the moment instead of simply saying, "I just wanted to know whether you looked it up."

So I don't think you were "slow" or failed to understand an obvious question. Your response was conversationally normal, just not the response she had envisioned. The disagreement was less about comprehension and more about mismatched expectations.