Oh that's why she glared at the teacup earlier on in the series, she had Rona slip love potion into the tea, that's why she fell in love with Angela in the first place and did so much to help her... she probably spiked the tea/cake she brought in to Cassiel the first time too...
No wonder she got her claws into the second prince and her father too, she probably put love potion in their tea and stuff...