They both can be spoken, but unlikely to appear as the written word (there is a contextual requirement that is necessary to complete the ideas, and that normally only comes from conversation: the creation of an unstated but understood thing that completes the sentence in oral communications). I am a native speaker of North American English and a fairly avid reader.
Now she would know means that "something just happened, and this will (eventually) lead to the information becoming knowledge of that lady (the she of the sentence). What the event that just happened actually is, though, was not declared.
Now she WILL know also turns on the occurrence of an event (likely one in the recent past), but instead of an uncertain in timing of the eventual passing of information to that "she", the timing will be rapid and she WILL know, and likely very soon. It is impossible that she will be able to remain ignorant.
The difference between the two turns on whether there is any remote possibility that she is ignorant of this information at any possible future time (thus would; only a possibility not a certainty), or whether it is certain that the knowledge will come to her (thus will, an inevitable future result).
If you were writing a text and wanted to express those ideas, you would be expected to include the "if" part, the condition that gets satisfied first and leads to the would or will result.