Did I attend an assessment with you for this client in question?
If so I remember the client didn't want to be reclined back too far and so the Burnett bath support wasn't suitable.
The clients parent was suggesting something like the seat on her wheelchair.
Have you seen the custom bath seat by special Orthotic, Services?
Its very much like a moulded seat within a wheelchair but for the bath, this is suitable for children and young adults.
you can check out the product profile page-> www.made2aid.co.uk/productprofile?productId=2&company=SOS
If you like the look of the product click the request an assessment box and they can arrange an assessment with you direct.
If not the Jon-Vac Bath support is very similar to the Burnett bath support however the back & Base is more flat so would most probably be more suitable for that style of bath as I remember you stating it was only a short bath.
Therefore it wouldn't bring her too far forward, you can view this profile here -> www.made2aid.co.uk/productprofile?productId=23&company=DCS%20%20Joncare
However there isn't lot of information on this as its only a new product. again if you like the look of this product there is also an assessment request box.
I hope that this is of use to you, If anybody else has any suggestions please leave a comment.
I hope you resolve this soon