Did I miss something? Is she more than two years older than him? Because, if not: regardless of her machinations and the execution thereof, she put herself in a position where
he had known and material leverage over her rather than the other way around. She never put him in a situation where he would have to rely on her (well, she didn't plan taking a mortal blow for him, prompting him to descend to Hell to heal her, which contributed to the waning of his powers and his informal defection from the Church's forces-- and even then, he's the breadwinner... in all applicable senses

).
Not every toxic relationship dynamic is "grooming", and it isn't "grooming" just because they weren't born on the exact same day, month, and year.