I've decided that this will be your "sweet-sweet"
Vague sentence but my interpretation is that miss decided to turn Reimu into "sweet-sweet" because Marisa yelled at her which she "interpreted" as Marisa being unhappy with having Reimu as a friend.
But it's also possible that miss had decided on making Reimu into "sweet-sweet" from the very start.How is it Marisa? Are you heppy with it?Hurch... mishter footsie... mishter footsie!Dwon't ged in the way!Puff! Puff-puff!Bwig shiiiiiiiー!Yu?Little shish!