You have maiden name and name after marriage forwife.... adn what about husband... my example is just like that... :-) i have taken my wife's surname after marriage... so i am openly offering you to consider to add this option (married name for husband) with next update.
Rather than adding a field for Husbands maiden name, I would suggest adding a field that could be applied to either the husband or the wife, and call it "Legal name", or "Chosen Name".
Several of my female family members use different family names. One uses her maiden name, even though she is married, another uses a hyphenated name with her husbands name coming first. I have heard of some females using hyphenated name with the females name coming first.
I have another sister who still uses her ex-husbands last name, even though they are divorced. Her name is not shown correctly, no matter which naming preference I choose. If there were a field called "Chosen Name", the user could enter the name exactly as the person chooses to be called, and your software wouldn't have to figure out whether the person is married, divorced, hyphenated, etc.
...well "...hyphenated name with the females name coming first" you can meet this for e.g. in my native country Lithuania...
but i would say that a field with Husbands maiden name is neccesary (as per my own example). So, there are maiden names, the names after marriage and both being legal ones. Only then comes as you mention "chosen name". as "chosen name" it's not necessarily legal name, but rather as you have said "as person chooses to be called"...
In addition to the instances detailed in the previous messages, surnames for males (or females for that matter) change or evolve during immigration too. For example, my grandfather was born Czudek in Austria/Hungary but died Chudek in USA. So the idea to allow both birth names and other evolved names will be good. I also believe it is custom in Spanish heritage that the man takes the womans surname (if I recall correctly).