Hi and welcome!
We do try to be gentle here on Rootschat, I hope.
I guess there could be all number of reasons why someone uses two names.
And I guess the only way to find out more is firstly to send for the marriage cert. Then maybe by investigating the person further the situaton may get clearer. At least they are not covering it up - that is when it gets hard, when someone married in a different name to that they were born with!
All the best with your searching - and dont be shy about askingf questions on rootschat