John Surratt's real parents?

[Eva Elisabeth]

As for the purpose of gaining a prisoner exchange, that intent was kicked down a notch when Grant ordered the return of prisoner releases. I think Booth's plan for that issue was to get those Southern prisoners released...

I've tried to ask this before - can one of those who believe on April 14, Mary Surratt still believed abduction was to be going on please explain to me what she might have believed what was to be achieved therewith regarding the intent (and sense) had become obsolete by that date?