As you were not married at the time of birth and your daughter is under 8 you need to go to the family court to get full parental rights which is required by Immigration to get a 12 month extension. Is that what you mean by "went through the courts to legitimise my daughter" because I thought that was expensive and took some time?
These are the in country general requirements for the 12 month extension, expect the visa requirements to be similar. Are you the registered parent as that is normally the toughest requirement for Immigration?