you mean 3 weeks right?? Whether its 3 weeks or 3 months, they seriously need more light. Move the lights down closer to the plant because they're really thin and stretched out. As long as you have proper airflow, you should be able to have your plants within 1 inch of the CFL's. If its really 3 months, you should probably flower it now because it wont it wont support much bud and letting it stretch even more would make the problem worse. Cut your losses and start a new, improved grow. Dont let a weak plant hold you back!