Swamped

You look her right in the eye.

"Look. I don't really care about why you're chasing this one person, what else you're doing in town, or why you look like at least three other people I've seen tonight. I just want to know one thing, and I think it's a perfectly reasonable question. Did you know my grandmother?"

She looks at you skeptically.

"Just how old do you think I am?"

Not actually answering the question, you can't help but notice.

"Not making any assumptions there. It's just that you seemed pretty interested in her map. Wondering how you heard about it, since I only knew about it because of her."

Now she's just irritated.

"We may be working together for the moment, but my information sources are none of your business."

"If they spied on my grandmother, I think they very much are," you reply. "And the fact you're not very eager to give me a clear answer makes me think that might be it."

She frowns. Then she gets a look of resignation.

"Consider this that you may know," she says. "If we did meet, it might have been under circumstances that aren't safe for me to talk about. So all I can tell you is that I'm not hiding things from you out of malice, it's merely caution."

Consider this that you may know
What beast was buried long ago

It's an awkward turn of phrase. So she's basically telling you that yes, she does know the poem. But apparently she's not willing to risk saying more than that.

You wouldn't say you're satisfied with that answer, but you don't think it'll do much good to push your luck. So you go back to the ostensible topic.

"Fine. I guess we'll have to leave it at that. So let's get talking about the old theater. Do you have some particular reason why you think it's worth investigating?"

You aren't expecting a straight answer, but you'll work with what you get.

She doesn't say anything, though. Just pulls something out of her pocket and shows it to you.