In most situations, a roommate is considered a renter, and their possessions will not be covered under the homeowners policy. home insurance covers the personal property of the home owner and their immediate family such as the spouse and children, but does not extend to other persons living in the home, even relatives such as your cousin or aunt.
What your roommate needs to do is purchase a renters insurance policy. This type of insurance is similar to the personal property section of a home insurance policy and covers the property listed on the roommate's inventory up to the limits of the policy. A typical renters insurance policy is for around $3000, but additional coverage can be purchased as needed.
To get the maximum amount of property protection, your roommate should take an inventory of their belongings which lists all of her property, from jewelry to clothing to any furniture or appliances stored on the property. It is becoming increasingly common for such an inventory to be in the form of a video recording which shows the exact items insured and offers the insurance company an idea of the condition of the insured items. Don't forget to include receipts for the insured items to verify your ownership. Keep in mind that insurable items do not have to be stored inside the home. Lawnmowers and shop tools are included in property insurance, along with stereo and TV equipment, a washer and dryer, or the pictures and other collectible items the person owns.