Wills and Power of Attorney

I hold a Lasting Power of Attorney for my mother's financial affairs,as she is now in a care home suffering with dementia.A few years ago,prior to her illness,she decided to change her will.I have just read said document and discovered that certain proportions of her estate are wrongly apportioned and,although the document is witnessed,it is not signed or dated by my mother.

Can anyone tell me how this leaves the legal situation and is the will valid?



thanks

Wills and Power of Attorney