How do I sponsor someone if have never meet in person

More information is needed to assess the matter. It is not clear why you wish to bring this person to the United States. Assuming you wish to bring this person to the United States to marry, your option is limited to a fiancé visa petition. Typically, you must have met in person within the past two years to qualify for a fiancé visa petition. However, there are exceptions if you can demonstrate that you cannot meet due to hardship or due to religious/cultural reasons. Requesting an exception is never easy but if you can document your mother's need for care, you may qualify. You can read more about the fiancé visa petition at http://myattorneyusa.com/k-1-and-k-2-visas-for-fiancees-and-derivatives.