There are several ways to go about this. If your friend has a travel insurance policy with solid medical coverage, that may be all she needs. However, not all travel insurance policies with medical coverage meet the standards required to obtain a Schengen visa, so she will have to get this confirmed by the embassy or consulate preparing her visa.
An alternative is for you to take out guest insurance. Many Swiss insurance companies provide guest insurance and coverage generally meets Schengen visa requirements. Once you have taken out the policy, you can forward your friend a copy to use for her visa application.
You can read more about guest insurance here:
http://www.moneyland.ch/en/health-insurance-for-guests-in-switzerland