I did a Pomeranian from an absolutely wretched photo--tiny, blurry, almost bizarre really. I called it the Nightmare Drawing From Hell and I wasn't exaggerating.
Good luck. I'm utterly baffled that people don't understand the better the photo the better the drawing. I suppose they don't get that a cute photo is not necessarily a 'good' photo.
You'll do fine, there's enough there, just barely.