Yolanda
"That is good then. Those creatures cannot be killed with a weapon such as that."

Suke would say and point her finger at his wooden sword in Mehki's possession. 

"So it will be still lurking around the area after some time to recover."

She had a roundabout way to defeat the heartless, though since Ika wasn't around it made getting rid of the Heartless much harder.
Shirley
"Yeah I know I dealt with them before" He said scratching the back of his head as he remembers that you need a keyblade to actually defeat them but currently he didn't have to power to summon it yet though he thought to ask this person something "I gotta ask are you a heartless? Because i sensing a similar what should I say darkness between you and them" He thinks that she probably not a bad guy sense she told him that his wooden sword wouldn't work even if he already known that before hand
Yolanda
"Oh, so you're familiar with them?"

Suke thought he was from this world and guessed that this was more of a natural occurrence then she thought. She then gave a small nod at the next question, as she saw no point in lying. 

"I am a Heartless, given a more human form. Though my memories are lost to me: I have one drive that drives me to fight other Heartless."
Shirley
"Wait that's possible?! I never saw that before welp I glad you on our sad miss heartless lady" He said not knowing her name