I can understand your frustration to have lost jobs for both people in the family, & it may look unjust from one point of view; but it's the struggle in life & sometimes we have to accept it.
If you have left the company thinking that you could still depend on her salary for income, then the reason behind this unrest is your 'career choice risk' & not the company's 'Illegal termination issue of your spouse'.
Since they relived you in 1 day & relieved her without notice, it seems you do not have any contract signed for reliving period. In that case, it is not illegal to terminate the employment contract from company, given due reason.
If the company has said that she is relived due to "No further requirement" to the organization, then that's a fair reason. She can pursue her career further without any dent on her professional record. Why are you so much worried about what the actual reason would be? She has gained experience & salary for 5 months. How can it be waste?
You said you were on bench for 4 months... It may be the fact they really do not have work, & were retaining her just because they were retaining you. The priorities for her release over other employees might have been increased, when you left.
I really do not think you should argue, or can win this argument with that company..... Sorry for that!
Best of luck in pursuing your next job, to you & your spouse as well!
8th May 2015