Oh, I started to cry reading your post. My father, just prior to his 80th birthday passed away after having suffered a massive stroke a few months prior (this just happened a few months ago so I am still very tearful over it - hence the tears when I read your post). Just wanted you to know that speaking from this perspective your friend just needs time and is more focused on her father's situation than what you did. Honestly, everything that happened in the months between the stroke and his death was a blur for me. Clearly you are an awesome, caring friend - everyone makes mistakes, just be patient and forgive yourself.
Take care.