She will have to carry out the full registration proceedure even if she is only looking after your child (doesnt make any difference if its a relative or not). So she will have to start with the following (England)
Contact local authority - they usually have a couple of sessions where you pop along for info.
If she still wants to go ahead then their is a pre-reg course which is usually one evening a week for about 6 wks.
Complete Ofsted registration applications, have CRB check done, medical by her GP.
This info goes into Ofsted with the application and they check suitability, if thats ok then they will call out for an initial safety visit to check the house out and ask her questions about how she plans to work / look after mindees.
The application process can be quite lengthy so if you are wanting to switch over I think you should get going asap some can take upto 5mths.
She will also have to do certain courses as standard Paediatric 1st aid (12 hr one), Safeguarding L1 (minimum) L2 is also good to have. EYFS training as she will have to follow the curriculum and carry out observations / planning / assessments onm your child. She will also have to register as a food business with environmental Health who pop around to have a look.
Also will be required to do Risk Assessments for just about everything you can think of and a bit more, policys and proceedures relating to business practice and care of the child. Register as Self Employed with HMRC and keep accounts pay own tax / ni cons.
She will also need public liability and extra car / home Ins.
Childminding isn't for the faint hearted and I would'nt register for only one child but she could start looking after others as well if she wanted.
She will also have a full inspection within 6mnths and then every 3 yrs thereafter.