Francisca
She stared in shock when the man stopped to speak to her, asking if the woman was capable of doing magic. Instinctively she shyed away, stepping back as she clutched the wand silently, her eyes darting back and forth as they traced along the ground. Chi-Chi moved to speak, but then paused again, faltering as she tentatively nodded as if unsure of herself, only to stop and hug the wand to herself.

Finally, she nodded again, puffing herself up in pride as if to fortify her answer. For she was totally good at magic, she was a master of body mind and spirit at this point, and surely the young woman could use actual magic just as easily as the magic from her books.

Studying the man now, she realized he had to have been of the Tretons, the half-fishies. She jolted up in remembrance, and turned to dig around her satchel for a so-so seashell (as she was not going to give him one of the nicer ones), finally turning to produce it from her bag as if offering it. Thinking back, in chapter nine of the second Magi-Meni book, the protagonist offered a Treton a seashell as a gift. Perhaps the same custom applied, and so, Chi-Chi held out the shell, insistently.
Gregory
*He could see her shyness from the woman's face when he asked her the question and was waiting for the answer. Then he thought she was about to speak, but she simply nodded, another sign of shyness. And her movements with the wand made it seem like she couldn't really to do magic and this was in her own mind. Even though she nodded again to confirm it he still didn't believe it and was about to ask her to prove it when she offered a sea shell from her bag. 

He was confused to say the least. He also collected sea shells sometimes but couldn't figure out why this lady would offer one to him randomly. He stared at it for a while not knowing what to do but then his curiosity got the better of him again and he took it from her hand with haste so that he could look at it closely. He put it in front of his eyes and rotated it again and again, carefully studying it, then he realized this was a "Meh" Seashell so he decided to confront the woman about this. 

"You can find this kind of sea shells easily, also why did you give it to me for no reason?" 

*He threw the sea shell into the sea with a swift hand movement and looked directly at the woman*
Francisca
The woman blinked slowly as she watched the man take it, smiling brightly for a moment as she seemed beyond delighted that he accepted the gift, lifting the satchel into her arms and hugging it as she observed the way he inspected it—only to see him discard it into the ocean immediately. Her expression seemed heartbroken for a moment, a defeated gasp ringing out as she hurriedly bowed her head in shame.

Of course the gift wasn't worthwhile to him, it wasn't nearly the best shell she had. Tentatively, Chi-Chi lifted her head as she sniffled, holding out a much nicer and much larger shell as a gift. Her expression made it clear that she was presenting it despite her clear fondness for it, falling to her knees to hold it out insistently. The wide-brim of her hat covered her face as she tried her best to think of what to say, only to finally whisper out a few words.

"P-Please take it..." 

Her voice was soft and ridden with guilt, the seashell itself was more than definitely worth it's price at a market or anything similar, and if it came down to appeasing this man, Chi-Chi would be fine with such a sacrifice.
Gregory
*His face suddenly expressed sadness as he thought he was guilty because he had made the woman sad by giving her a moment of hapiness and then taking it away. He couldn't forgive himself for this so he didn't say anything and looked down in shame as well. Then he noticed the lady's movement and didn't know what she wanted to do, but then she pulled out another sea shell that was far better. Then he struggled to speak as he still remembered whar happened earlier*

"S-ss-sorry for earlier, I- I didn't mean to make you sad, can you forgive me?"

*He took the shell and looked at it, knowing that this will be a fine addition to his collection, making him happy again but he was still waiting for the woman's forgiveness.*
Francisca
The woman stared in shocked silence at the change of behavior, noting that he *Did* Feel bad now, and was asking for her forgiveness of all things. She was surprised considering it was her own fault in giving such a mediocre gift, if anything Chi-Chi felt like the one that needed to apologize. Yet she remained silent, watching the man take the shell made her relieved enough to let it pass, smiling as she wiped her face.

She bowed again, trying to think of what to say. "I... Forgive you..." Staring at the shell in his arms though, she pursed her lips and hid her frown. "P-Please enjoy the gift." Bowing her head again and shutting her eyes, the girl hugged her satchel tighter to herself, only to turn away, now trying to make her way from the situation entirely now that it was dealt with.