Hello, I'm Keith and happy to help you with your question. Please remember that in the UK a husband and wife are separate legal entities for taxation and each must submit an annual self assessment if required.
Firstly let's get rid of your wife [Who said that?] When she left the UK did she complete a Form P85? If she did not she should do so immediately. The form is available on the net and can be submitted on line. There is no time limit as to its submission. On receipt of the P85 HMRC will classify her as non resident for the tax year after her departure date and furthermore split the year of leaving into two portions, one resident and one non resident.
Now let's consider your position. You must contact your tax office and grovel. Charity is in short supply in HMRC and there can be penalties for non submission of returns. However even HMRC does not wish to process returns which yield no or insignificant revenue so I would be inclined to kick off with a letter giving an indication of the sums involved. Your tax office may just note it and tell you not to bother. They certainly did with me last year.
I do hope I have shown you a way forward in this matter.