My client with dementia has still not transitioned. Will another session of subconscious channeling help her to see the wisdom in this? What else can be done?

Doing another session is an excellent idea and may well create the momentum needed for her to transition which is the desired end goal after all. Through all of what is being done, keep in mind that she still retains a free will and, to that extent, there will be uncertainties always in doing work of this kind for clients. Their thoughts can be the overriding and determining factor in reaching a critical threshold to tip the balance towards making a transition or not, so we support further effort here as it is still in her best interest to exit at this point.