Weeks ago when browsing through petfinder, I saw a dog listed as a mini lab and she was said to be about 30 lbs and she was about 1 year old if I remember correctly. Is there really any such thing as a mini lab?

No, according to the breed standard, there is not. There are a lot of ill-bred Labs and half-bred Labs that are very light, but they are ill-bred and half-bred.

(avg weight per AKC: 55 to 75 lbs)

http://www.akc.org/breeds/labrador_retriever/index.cfm

If it was on petfinder, it probably is just a lab mix. As the poster before me stated, according to the breed standard, there are no such things as a mini-lab.

I remember a while ago someone coming up to me and saying they had a mini-lab. I believe I said, "You mean a small lab?" Irie is under the standard weight. I guess I have one of those rare mini-Labs and I didn't even know it ;)

There is no such thing as a mini-lab, but it is possible the dog is just small and will stay like that.

There is no such thing. They come in different sizes. It's probably mixed with something. My 1 year old is about 50 lbs. She is definitely on the petite side for a lab. But she's also definitely mixed with something else...greyhound or pointer maybe...

Our obedience class had what DH and I called a "Mini Lab." She was actually a lab/terrier mix. She looked perfectly proportioned to Bradie, but stood about 18 inches high at the shoulders. She was cute.