well, not necessarily. Yes, majority of the time grooming has a sexual connotation, but the act of grooming itself has more to do with manipulation towards a objective that is harmful.
For example, someone can groom a child to commit robbery, they manipulate the kid to think its cool, that they can become rich or become a grown-up by doing it, etc.
So far she hasn’t really done anything to groom him. She just tolerating him basically. We’ll have to see if it’s really grooming or if she just takes advantage of his feelings for her.
Do we really care either way? Either way he’s still a creepy traitor, that should have suffered more than loosing his title

Grooming generally revolves around sexual abuse right? But Annetta and Hermann doesn't have that relationship at all because Annetta was in love with the first emperor despite being betrayed. Maybe she only harbors only hatred in her heart but she used Hermann and his family with revenge in mind. And Hermann also wasn't under Annetta's control when Regina and Hermann met and it only happened at a later date ┗( T﹏T )┛ this is confusing because it seemed like Annetta really did view Hermann platonically and Hermann's love was unrequited (╥ ω ╥)