DLA SUPERCESSION

Hi there,
My 80 year old mother had a visit from an OT from the council who also did a benefits check, and advised that she most likely should have been in receipt of hmc or lmc.
my mother has been in receipt of LRC since she was 55 and never informed dwp of her worsening conditions (before age of 65). she has received a form DLA 434 looking again at adults , and a dbd 420 asking for reasons for requesting it to be looked at again. I'm absolutely confused on how to complete the form and obviously at the moment cannot get access to much assistance for advice ivo coronavirus eg any form filling services. Should the information be provided as when she was 65 or as she is now at 80? also what should we put down as the reason for requesting a revision/supercession? not knowing re providing information at the time? can't see anything in the downloads covering this.
any help with this would be greatly appreciated
thanks

thanks Gordon, yes her care needs and her mobility needs have increased since she initially made the claim in 1995.