The Power of the Pack by Maggie Ryan

With an ancient evil once again threatening to destroy everything she loves, Cassandra Ambrosia grows ever more determined in her search for the truth about herself, and at last she makes a discovery which could hold the key to finally breaking the curse on her family forever.
As Cassandra continues her hunt for answers, however, her mates struggle to keep their headstrong little human safe from both her enemies and her own recklessness. Deo and Draco do not hesitate to correct Cassandra as thoroughly and shamefully as they feel it necessary, yet even when her cheeks are blushing crimson and her well-punished bare bottom is sore both inside and out, she cannot help delighting in the hard, dominant lovemaking of her two alpha mates.
But the final battle is drawing nearer with every passing day, and even a wolf and a dragon cannot overcome the foes who approach on their own. If the Ambrosia family hopes to survive, they will need more than just their skill and courage. They will need the power of the pack.