At the end of the day, the main reason, direction and purpose of Mr and Mrs Wanky was the baby and not the mother. They needed legal status for the baby, for the first grandchild and the heir could not be born out of wedlock!
They had decided finally to let Thalia be his fiancée and were even considering marriage to establish the baby's status, after which he would have to divorce her and marry a 'proper wife' of their choosing. If their plan went according to the script, that was supposed to be the outcome. The main characters of the supposed script, Charles and Thalia, were blindsided and had no idea that they were in such.
In these six weeks that passed, many things happened in the Wanky household that Thalia did not know how to feel about. In essence, all she had then was the hope and the trust she had in her fiancé.
