Speaking of England, if you move before your daughter is 18, you should contact the local authority's Special Educational Needs Team. She may be entitled to education until she is 19 years old and then possibly college for another two years. Other UK countries may vary slightly.
I would also suggest that you contact the local authority's social care department and request a Child in Need Assessment under s17 of the Children Act 1989. Each LA runs their departments differently. Some will have a central referral and assessment team and others will have a disabled children's team that you can refer directly. The website should explain it. As MLG suggested above, CAF is a recognized assessment but as your daughter is 17 years old and time if of the essence, I would recommend that you go for the legal duty for authorities to provide a CIN assessment which may identify support services. They will also signpost you to Transition or adult services as necessary. Do not delay.
Of course this is subject to some sort of leave to remain in this country. These are considered Universal Services like health care that children are entitled to as long as they are a dependent of someone who has leave to remain in the UK.
http://www.cafamily.org.uk/ - great organisation!
Online legal handbook with loads of info!!
http://www.councilfordisabledchildren.org.uk/resources/cdcs-resources/disabled-children-a-legal-handbookFeel free to PM me if you wish. I am a social worker for a London authority and this is my area of expertise.