Be patient and consistent. Do not try and feed and get her heavier as fast as possible. In the end you will just end up with a fat and unhealthy gecko. If this is in attempts to get her ready for breeding you will only hurt yourself in the future. Keep fresh worms in her bowl every 3-4 days with proper supplements and she will gain weight naturally and in a healthy way. Be patient, she will get there. Good luck.
Greg