The client can still sign the legal help form provided the criteria in the contract below are met.
B4 Application from a Child An application for Controlled Work may not be accepted from a child unless: (a) the Controlled Work is in relation to proceedings which the child is entitled to begin, prosecute or defend without a litigation friend, next friend, or guardian ad litem; or (b) there is good reason why any of the persons referred to in Rule 5 below cannot seek advice on the child’s behalf and the child is old enough to give instructions and understands the nature of the Controlled Work.
3.19 Good reason for the purposes of Funding Code provision B4 above will include, but is not limited to, situations where there is a conflict of interest.
3.20 Where Controlled Work is provided directly to a Child under the Funding Code provision above the Child will sign the application form him/herself.
My understanding is that client will need a litigation friend to commence proceedings so a litigation friend can sign the form on the client's behalf. If one is not available then you can use the second limb if the conditions are met.