You may book an appointment with the UKBA to present the case for same day consideration. She will need to take the "Life in the UK Test"

IMHO she can take the test anytime as this does not have to be witin the 28 day period.

Some cases are decided pretty quick. However, I have overheard the UKBA official at Croydon PEO telling a candidate who had finished his biometrics that day that it can take up to 4 weeks for the ICFN to be issued.

I agree with girlpower19818. Why does she require an extension when she can apply 28 days before her 5 year qualifying period???

If you are on a old-style work permit, then the form to be used should be the FLR(O)

It can take between 4-6 weeks depending on the documentation submitted. Of course, if the UKBA need to visit the employer, it can take substantially longer.