Due to her alone, hell no. For one there's no way she didn't know that the infertility plague wasn't contageous considering she was living with the remnants for awhile and they knew a lot of details about it. How it spread, how much time they had till it arrived, etc., yet, she quept it quiet until she got to the island knowing full well it was a risk to the islanders. That fact alone makes her pretty dispicable. Knowingly infecting people is actually a crime. Don't even get me started on her "it makes me uncomfortable with you 2 being affectionate" manipulative BS...
Okay, considering when she arrived, that's a big assumption.
They'd been living with the "curse" for over a decade when she arrived. It was a fact of life, not an emerging problem. She was -- to them -- probably a dead-person walking. Why bother telling her about something that was irrelevant to her situation. So the chance of her not knowing it even existed is reasonable, even if surprising.
Of course she could have known, which would make her actions questionable, but unless it's revealed later that she did, there's no reason to believe she didn't.
If it turns out she was hiding it later, hopefully that'll allow the MC to adjust his opinion, but everything else about this game says that's not the type of story Pandaman is telling, so at this point you're just projecting traits onto her that she's not displaying.
EDIT: About the only thing that makes her even slightly creepy is the reveal that she had a thing for the MC before she was excommunicated and she didn't reveal it ... when he appeared as her savior with the apparent love of his life. As for the being uncomfortable with these new friends being intimate with each other in your presence ... yea, that doesn't make any sense at all...
