Here's what looks like the baptism of Frances Betts (irishgenealogy.ie):

Area - DUBLIN (COI) , Parish/Church/Congregation - ST. MATTHEW
Baptism of FRANCES BETTS of IRISHTOWN on 18 March 1838

Name FRANCES BETTS
Date of Birth 2 December 1832
Address IRISHTOWN
Father THOMAS BETTS
Mother ELIZA
Father Occupation SCHOOL MASTER

There are also baptisms on the site for siblings of Frances. Her marriage to John Miller is also there, + lots of other Betts records who seem to be related in some way.

Happy hunting!
Colette