Can a 6 month old have insomnia?

My daughter is 6 months old and refuses to take naps.She yawns and rubs her eyes and gets cranky so I lay her in her bed and give her the pacifier and she fights sleep and will not go to sleep. She even tries to fight it at night time but she sleeps about 5-6 hours and i have noticed she is starting to get dark under her eyes, is this because she isnt getting enough sleep? What should/can i do?