I don't know what the law is in her state, but in Washington State they DO NOT recognize Common Law Marriage. I also learned you can have a ceremony but if the minister or you DO NOT register the original certificate with the County Clerk as far as the County is concerned you are not married since they have no record of it.
Only a few states recognize common law marriages, and each has specific stipulations as to what relationships are included:
Alabama
Colorado
District of Columbia
Georgia (if created before 1/1/97)
Idaho (if created before 1/1/96)
Iowa
Kansas
Montana
New Hampshire (for inheritance purposes only)
Ohio (if created before 10/10/91)
Oklahoma (possibly only if created before 11/1/98. Oklahoma’s laws and court decisions may be in conflict about whether common law marriages formed in that state after 11/1/98 will be recognized.)
Pennsylvania (if created before 1/1/05)
Rhode Island
South Carolina
Texas
Utah
https://www.unmarried.org/common-law-marriage-fact-sheet/