Assistance with fruit tree

Hi everyone, I am very new to gardening, and my 94yo grandmother has a fruit tree that she is gutted about and looking for any advise – so far she believes that the tree will effectively die and it cannot come back from the damage

This is an offshoot growth from a very old fruit tree from her childhood that is now 1.5-2m tall.

A gardener whippersnippered the trunk of the plant. She believes that because the bark has been stripped completely around, this fully stunting the vascular system.

Any advise around what she can do is appreciated

I believes it’s either peach ir nectarine but I’m not confident