Details that are "factual" are details or pieces of information, that can be proven to be true and accurate--scientifically, realistically, etc.
Answer:
Banquo is skeptical of the Witches’ intentions and remains unconvinced of the Witches’ prophecy. Banquo warns Macbeth that “instruments of darkness” often tell half-truths “to win us to our harm” (1.3.125–126). While the Witches have prophesied great futures for both Macbeth and Banquo, Banquo is less inspired and intrigued than Macbeth and would rather leave the matter safely alone.
Explanation:
It’s probably best to be straight up and ask. But if you don’t want to do that, you could just mention her up in passing. Such as “Hey did you see what Anna posted?” (let’s say Anna) or maybe some thing like “hey I literally thought I saw Anna at Walmart” and then when this person is somehow brought up, you could be like “speaking of which, I didn’t see her at the party? Everything okay?”