Dwarves and trolls have had a rivalry going back millennia but in my Fairy Kingdom dwarves are also at loggerheads with the elves. Dwarves consider elves too much up themselves to be worth befriending. Elves consider dwarves dirty little oiks for spending so much time underground mining.
Witches don't trust wizards either (mind it is hard to name a species witches do trust). Wizards consider witches inferior (though it is either a brave or foolish wizard to actually say so directly to a witch given 500 years before the start of The Trouble With Mother a witch detonated a young wizard for being sexist in her presence. This led to riots - wizards very much consider themselves the past masters at blowing things apart - and it took the intervention of the Fairy Queen's aunt, Graxia, to stop all this and calm the realm down).
The Kingdom is united on some things though. Pixies, imps and other sprites are to be despised for being the mischief making troublemakers they are. And Eileen should never have defected to marry a mere human male. Eileen, in the realm's eyes, has very much let them and herself down badly here.