Yeast infections are terrible things to deal with. No wonder Elsa had looked so uncomfortable. She's also limited in her options, too. No tablet. No pessary. No applicators. In the words of the pharmacist, "just use a finger". Elsa had blushed bright red and Anna had focussed on it because it was better than the alternative.
Actually, she distracts herself with thoughts of Thanksgiving, even though she's mostly talked herself out of inviting Elsa – surely the blonde has her own celebration? But then Elsa brings it up on the way home, asking if they can do it together.