Spouse Visa Application from within UK

[t4ure4n]

I am in UK since September 2004 on Student Visa and I have been married to a British Citizen since April 2011.

I want to apply for spouse visa. My Wife has only been working for 3 months (since June 2012). Her annual salary before tax is over £19,000. She hasn't worked before June 2012.

Can some one advise me if I can apply for spouse visa with only 3 payslips. Some one told me that If the current employment is less than 6 months then I have to show same level to income/access to finances for 12 months prior to this employment and it should be at minimum £18,600/year.

Is that true? Or there is relaxation for some one who is already in UK. And whose spouse has been working for less than 6 months?