“Yasmine Galenorn’s Otherworld Series. {Also called the Sisters of the Moon Series.} It’s about 3 half human-half Fae sisters who live on Earth and are trying to prevent a demon uprising.
Each sister has different powers that go wonky due to their halfblood nature: One is a witch whose spells don’t always work in the manner she wishes, the second is a werecat who ends up turning into a tabby instead of something bigger which as you can tell, doesn’t always work for a battle, and the third was a skilled acrobat until she fell into a vampire meeting while spying on them and was turned.