This is wrong because an adverbial phrase <span> the term for two or more words which play the role of an adverb.
this does not include your sentence, here is an example of what i am talking about.
</span><span><span>I will sit quietly.</span>(normal adverb)<span>I will sit in silence.</span>(adverbial phrase)<span>I will sit like a monk meditates. </span></span><span>(adverbial clause)
The wife is old, ugly and lowborn. Even the knight tells it to her on their wedding night. It is also decadent for the knight who might have been wed to a beautiful woman. Therefore, the woman is really careful and shrewd. Using her wiles she tries to make the knight marry her.