Mrs + male name

[googl]

Dear teacher,

what these constructs mean?
1) mrs Smith
2) mrs Jane Smith
3) mrs John Smith (male name??? typo for 'mr'?)

[Alan]

Mrs = Missis (a term of address for married women).

'Mrs John Smith' is possible: it is a formal, rather legalistic, way of referring to the wife of Mr John Smith.

'Mrs Jane Smith' would, of course, be the married lady's own name.