Which records do you have for each name? Are you asking if Mr. Teer had two wives, one with the surname Young, and the other Younger? Consider that some of the records may not have been reported on by Sarah, and that her name could have been bungled. (Mother's maiden name on one of her children's death certificates, for example.)
Your quickest bet is to use the censuses for years before her marriage to search for Young and Younger families in the places where she lived. If only one surname shows up, you've got your most likely conclusion.
