What security clearance? No one in their right mind would give Huma Abedin any kind of security clearance, given that both her parents were radical Islamists and she spent most of her formative years in Saudi Arabia.
In order to get a security clearance, you have to first fill out a detailed background questionnaire for the FBI. At least that's the traditional way it was done. Huma should have been ruled out for any level security clearance if she had the temerity to apply for one.