Omegaverse
Omega who never truly develops his maternity instincts towards his daughter. He gives birth to her because his alpha wanted so. He loves his alpha, of course. But their daughter always felt like a burden. But he raised her properly like a mother should.
I think Rosie should marry Vox to get back at Alastor for breaking the deal.
Think about it. It's poetic! The very 'tool' he used to break his chain is now bonded to her. Perfect.