hello MrsSnape
I agree with Bubble EO is a good place to start-but also have a look at HE-UK-an excellent independant HW website.
Most importantly see HE Special needs
This page also has an email support list for families who home educate their children with SEN. I cannot recommend that list highly enough. There is a wealth of people there who will be able to lend support, as they know about home educating young people with the difficulties your daughter is experiencing.
You are right, the first step is to tell the school-there are a couple of differences between England/Wales and Scotland, so I'll bump up the relaveaant threads that tell you what to do.
There is a sample deregistration letter available on the EO and HE-UK websites. It is then the schools responsibility to tell the LA, not your mothers.
It is unlikely that the LA will be able to offer guidance on what your sister should be learning-as from now on it will be down to your mother and sister to decide that.
I would recommend that your sister (and her mom) take time to 'deschool'
"Deschooling is the process by which a child who has been in school re-acclimatises him or her self towards the new environment of home education from the school environment.
When a child is first removed from school the child's (and parents) expectations about what education is undergoes a period of reassessment. Schools follow a highly structured educational style with class learning regulated by the national curriculum and regular changes of subjects through the day. But its not just what is learned and how that changes, it's the institutional ethos. By this I mean the structured culture and authoritarian environment of school which of course plays little part in home life.
Sometime a child may have been traumatised by their school experiences. Perhaps by bullying, or the sense of being a small cog in a large institution. Sometimes it can be specific incidents leading to school refusal that leads to the decision to home educate. In these kinds of circumstances the process of deschooling is not limited to relearning how to learn, its learning how to trust in their own safety again. In this sense its the re-establishment of the child's concept of self and individuality.
Since their education has sometimes been bound together with fear and low self esteem then attempts to introduce formal learning into the child's life too soon after a removal from school may well be met with resistance from the child. It therefore can take some time for the child to see formal education as a safe and positive thing"
There are a couple of good books to look at on the 'Books on Home Education' thread.
I would recommend you look at 'Paths are made for walking:Home Educating our Autistic Spectrum Children' edited by Terri Dowty,
"The Teenage Liberation Handbook: How to Quit School and Get a Real Life and Education" by Grace Llewellyn
and
Unqualified Education: A Practical Guide to Learning at Home Age 11-18
By Gareth Lewis
details of all of these books are on that other thread.
Then I suggest looking for other home educators locally and going along to a HE meeting for a chat.
There is an email support list for Home Educators who wish to take exams they will be able to help you look at the options available.
Some home educators do take exams by the age of 16 (or earlier) some wait until they are 16+ and then do them at FE college when they are free, and some bypass GCSES and A levels altogether and do OU courses instead.
The choice will be your mom and nieces now.
Hope that helps-but if you do have any more questions do come back and ask.
I'll go bump up those other threads now.