I've seen this before. I gave some one sans and they had them in their dark living room for years and almost didn't know what they were. I believe they are Sansevieria trifasciata. The basic species. They need sun really bad. Put them in a bright spot but not direct sun. Direct sun at this stage will burn them. Sans are very tuff plants and can take a lot of abuse except over watering and low temps in the 50's. Once in brighter light, they will pick up and could grow up to 4 feet tall in 10 years.
Also they like a free draining soil. Regular potting soil holds too much water. I mix mine with 50% perlite. Sold in most big box stores cheap. They need very little to no fertilizer.
