@dethduck They are under 10 years old girls. I reckon girls that age typically love to have some really good, trusted female friends. They wouldn't yet be interested in relationships in a mature way, so no such flags should be rising. It would be very basic groundwork at best.
Unintentional lady/man-killer Katarina strikes again! Will there be no end to her adorable seducing ways?! Tune in next time on "How I Accidentally Got A (Polyamorous)Harem!"
It's a little refreshing to read an isekai story where the protag isn't stupidly overpowered (and the setting doesn't feel negative at all). She's actually having gradual experience built up over time.
Is it just me or did Mary look jelly when protag-chan was hitting on the white-haired girl?