Whether you intend her to be self-employed or employed, you'll still need to notify HMRC one way or the other.
If you intend to pay her self-employed, then she has 3 months to notify HMRC that she'll be self-employed, then she will have to file a return on Jan 31st 2015, like the rest of us.
If employed, you need to register as an employer, and notify HMRC (RTI its called i think) each time you pay her, either on the day before or the day of payment, even if it's nil tax and nil paye.