Hi, That's a good one!
She may well have kept her other married name.
Depending on the year, you could go back in records to find the info.
Mid 1800's depends on how Mid.
If you say what year then I would tell you if you could look back any records.
I have found that an extra surname is either the mothers maiden name or the fathers mothers name.
As I say just depends on the year of the marriage.
Maggsie