A school will take her IF they have a place in the correct year group. However, this is less likely to be a 'good' school. It will be an under subscribed one.
She may be able to do some subjects in one year but it would depend on their timetabling, and it would be a no no for some core subjects especially, unless she has the equivalent experience and knowledge of those finishing year 10 in her chosen school.
A college system may work better for her, with a reduced number of subjects - focusing on core subjects such as English Lit and Maths, and subjects she may want to study at higher level.
Most places, be it school or college, will be reluctant to admit her straight into A levels a year early unless she can prove she has GCSE level qualifications in those subjects and at the right grades. Even then some may say no until the year she turns 17y.
Many schools and colleges no have a year 14, so an extra year at school than the current norm. So even if she did go into Year 10, and drop down a year, she wouldn't be on her own doing A levels at 18-19y.