family celebrant

Noun

 * 1) A person who conducts weddings, civil unions, naming ceremonies, and other celebrations of life events, but who is not a government or church official.

Usage notes
Some people consider funerals to be within the purview of a family celebrant, while others restrict the term to people who only conduct ceremonies for family milestones, and use the term for someone who also conducts funerals and memorial services.