The IELTS test certificate has a validity of 2 years.

Maritess can apply for ILR 28 days in advance of her 24 months anniversary of living in UK.

Just for info here is the latest UKBA approved English test listing


You'll notice there are quite few different tests and different providers that can be used. Doesn't need to be IELTS if that proves to be inconvenient.

Does Maritess already have a Life in UK pass?

The UKBA plan is to introduce a new and slightly different Life in UK test October 2013 in addition to a new pass level in the English test to B1.
I doubt that Maritess will find that an issue as IELTS is already a minimum B1 level.