Hi Alex - by TIC I assume you mean that they have a form A restriction on the title so if Mum is now the sole legal and beneficial owner then
our PG 6 explains how to both update the register re the death (no ID form needed) and apply to cancel the form A restriction (section 7 of the guide)
You can lodge the forms AP1, RX3 and ST5 together along with the official/certified copy of the death certificate