Lost Cat, Gray 9 months old, West Street Historic

Our 9 month old cat got out into the yard and has been missing for about a week. If you see her, let us know. Her sister is missing her.  We live in the West Street historic district.
She is gray and small, about 8-9 lbs. Still a kitten. 
Very rambunctious, but friendly. Her sister gets out sometimes too, but never leaves the yard. 
She was leaving and coming back with trophies, birds/squirrels. Then, nothing.
Please let us know if you see anything...
wiklest@gmail.com