I'm surprised that this butler-kun wasn't made to be her fiancee at this point. Do this oujo-sama's parents know that she likes him?
Strictly speaking, their relationship isn't solid enough to approve of if the parents are thinking of the future. They might acknowledge that he's good for her, but are still deciding which one of them will need to step up and inherit the business.
Of course it's best if the daughter does it, but maybe they're waiting to see if she'll get strong enough to do it with the current setup instead of forcing an ultimatum.
Or maybe the parents are on a damn long business trip and butler-kun rizzed her up too fast.