The warning is from early morning to early evening of Friday.
The issue being even if she gets there, she may have problems getting back. If there are multiple road closures during to trees coming down during the day that might cause problems for her return even if conditions have improved.
There is talk that a red warning may yet be issued for some places (most likely Cornwall). It really isn't a 'normal' weather warning.
The last I heard was the advice was to consider whether your journey was necessary:
National Highways Head of Road Safety Jeremy Phillips said: “We’re encouraging drivers to check the latest weather and travel conditions before setting off on journeys and consider if their journey is necessary and can be delayed until conditions improve. If you do intend to travel, then plan your journey and take extra care, allowing more time for your journey.
Under the circumstances, given the advice and her additional needs, I think you'd be wise to keep her home because it is an exceptional situation. I suspect that some schools will announce tomorrow they are to be closed on Friday due to the warnings, particularly if a red warning is issued, which is sounding very possible.
I would see how things sound tomorrow but I think I'd probably not send her as things stand.