Your client will need a Court of Protection appointed deputy otherwise she will have no one with legal authority to manage her finances.
Although a family member may apply to be deputy, if the personal injury claim is successful and there is a significant compensation payout, I would recommend a professional deputy. It can be time-consuming and stressful dealing with the Court of Protection and the Office of the Public Guardian and a family member who is also trying to cope with the emotions and practicalities arising from looking after their disabled relative may find it all too much.
If the personal injury claim is unsuccessful, and the client’s assets are small, a family member may be preferable so that a significant amount of the client’s benefits are not spent on the deputy’s fees.
From the professional deputy’s point of view, if the client’s assets are very small, the deputy can end up doing a significant amount of work for which they will not be adequately remunerated. In a small firm, there is a limit to how much pro bono work can be supported.