No you can't.. Actually you can but depends on your and your cousin's nationality.. I tried my best but could not sponsor my girl cousin from Pakistan but my cousin from United States just took a flight and landed here bcoz she had an American passport. It was much easier before but now they have become very strict when it comes to visit visas. My cousin from Karachi has come to Doha 4 times in the past and there was never any problem to arrange visas but for the last two years, I have not been able to arrange a visa for her.. I stay here with my family (mom and dad) and I had all the proof that her father and my father are real brothers even then they just refused to give her the visa.. And my salary is much above 7K