* You must have been living in the United Kingdom at the beginning of the three- year period; and
* On the date that your application is received in the Home Office, you must have permanent residence/ ILR in the UK; and
* During the three-year period you must not have been outside the UK for more than 270 days (approximately 9 months); and
* During the last 12 months of the three-year period you must not have been outside the UK for more than 90 days; and
* You must not have been in breach of any UK immigration rules at any time during this three-year period of residence in the UK.

yes you need ILR, depends on your dates, as some people can apply for ilr and citizenship straight after.

once she has lived in the uk 3yrs then she can apply for citizenship