Absolutely. You mentioned her working with an assistant and the assistant getting killed, so I was just throwing in that 1) we could start from the beginning with you playing the assistant and them creating their first monster only to have it kill him and then you're character comes in later, or 2) I'll just make a journal entry flash back at the beginning to tell the story of her assistant, the creature and having to put it down because of her fear.. then your guy meets up with her at their place of employment and has ideas about creating something like what she did to see if biomechanics of that breadth are possible. 

So yes, she's created the monster, but put him down and buried it all in her memories. Your guy would call those back up. 

However - that is just an idea. We can work through various ideas too. Put your notes from the PM here... they are great.