Lab mix puppy weight

Question
We just visited a 5-month-old puppy at our local humane society that was labeled as a lab mix (as far as they can tell).  She is currently 10 pounds, and a worker there said that we should expect her to possibly as large as 40-60 pounds as an adult.  Does that seem likely to you?  We are looking for a dog that will get no bigger than 20-25 pounds or so.

Answer
The thing is that many shelters will throw Lab-Mix on just about anything that looks like a "generic dog".  And when you get a mixed puppy, you have no idea what's in there and what it will develop into as an adult.  A 5 month old at 10 pounds will probably not be 40-60# but if you are adamant that you want a small dog no more than 25#, I would stick to an adult or a known breed.  If the dog is nice, has a good personality and seems to suit your family, what's another 25#...I would be more concerned with a good dog vs. the size when picking a shelter dog.