were they married in the UK ?
if so, no, i think she needs to apply for FLR(M) as the spouse of a British citizen before her visa expires but as always probably better to apply asap.
Once married, your new wife must apply on a UK Border Agency form for leave (permission) to remain in the UK as a spouse. There are strict requirements that your wife will have to meet to satisfy the immigration authorities that the marriage is genuine and that she should be allowed to stay as a spouse. She will also have to show that she didn't intend to deceive the authorities when she entered the country as a student and that as a couple, you can support yourselves without help from the state once you get married. Permission to stay as your wife will initially be given for two years. Towards the end of the two year period she can apply to stay permanently.
