ILR and claming Benefit

[imran489]

Hello,
Can someone please advise me its very important about my wife visa,
My wife came in November 2012 under Tire 1 spouse visa, her visa expire on 6 February 2014, on the same date my ten years was completed, so I applied ILR and her FLR. I got my ILR and she got two year spouse visa. I also have a one year old son.
I am working full time Permanent job and salary is £19,000 p/a
Question 1: when my wife will apply for ILR, does she need to complete five year period, if yes why she has given two year visa instead of two and half year.
Question 2: I applied child benefit, child tax credit and will apply housing benefit next month, is that going to affect her further visa extension,
Thank you