Peggy
The silence returns, and this time it stays long enough for it to be palpable.
Then the shrill ranting begins.
"FOR FUCKS SAKE, ONE OF THOSE FOLKS?! LOOK, JUST BECAUSE I STRAINED MY VOICE AND WHERE HEAVY CLOTHING DOESN'T MEAN-"
Her voice is cut off by loud coughing, which quickly turns into something like retching.
...
When you hear that voice again, it's so hoarse and raw you feel like you're hearing an old man speak.
"...F... Uck... You."
After she manages that, she continuing coughing her throat out, or at least that's what it sounds like behind the closed door.
Robert
*Mevis would be surprised by the deep voice he had just heard. Well then, assume she was telling the truth, he could see why people thought the caretaker was a guy.*

*Still didn't answer if she was a ghost though, but Mevis realized in his stupidity he had a pretty easy way confirming. He would shift over his Oni mask over his face once more and turn on his thermal vision and then turn to face the house. This should reveal any heat signatures within 60 ft of him, meaning if she wasn't a ghost, assuming ghosts don't give off heat of course, he should see her frame through the door as anyone or anything else that may be giving off heat within 60 ft of him*
Peggy
As the results of the observation would show, the girl inside was perfectly warm and alive- a blob of heat hunching itself over as it shook uncontrollably. One could guess why it was doing so from the continuous coughs from behind the door.
Robert
*Mevis would let out a sigh of relief. Turns out he was being rather silly, and well, he owed the caretaker an apology. He would move away his mask, turning off the thermal vision with it, and sheepishly enter the house once more with his head held down.*

"Um, sorry, I didn't mean to get you upset like that... A-Are you ok? I've got some water on me..."

*Mevis would be mentally beat himself up for his poor actions. What he had done just now did not befit a hero, accusing someone of being a monster and causing them to get riled up. Worse, if the caretaker was still upset at him, he might not be able to get any information, cutting of the only trail he had in catching the assassin. His cowardice might lead to the downfall of this whole mission... He... He really hadn't changed after all*
Peggy
After a while, the girl stopped coughing, and looked back at Mevis, though while previously it was stoic, now it was just a dull look, though her eyes had shreds of frustration.

"What... Ever. Cut to the chase."
Robert
*Mevis would let out a sigh of relief to see he hadn't ruined his only lead. But he knew he wouldn't always be this lucky. He... Had to get get stronger, not only physically but mentally. That's the kind of hero he strived to be after all. 

"Um, so, I assume you have heard about the recent assassination in the town right? I'm a member of NS, Mevis, and I was sent here to investigate/capture the assassin. I had followed a lead that brought me to this part of town, but it disappeared after that. So now all I got to go off of is asking people such as yourself if they had seen anything unusual that day/night that might pertain to the assassinations. Think you can tell me anything about it?"