I don't see Ursula being interested at marrying Belle or in a tiny kingdom like the Beast's one.

I see Ursula as the witch that cursed him in the first place. Belle goes to the castle and has to stay for the same reason as the movie. Ursula tries to stop them from being together because she just wants Beast to suffer for something his parents did. She turns herself into a girl even more beautiful than Belle(Vanessa). She tries to flirt with him and even though she's prettier than Belle he just feels something about Belle that makes him love her. She hypnotizes him, breaks Belle's heart, eventually breaks it, Ursula loses, and the curse is broken.

@KataraLover I'm not sure Ursula would waist her time in such thing. I mean, her actions in TLM may have a little vingance reason, but all she wants is the power.

I think Ursula would just not fit right.

Animaluco maybe part of her power is revange and the desire for chaos

i can't see Ursula fitting at all