I think she was scared for him. Her powers are to heal people of physical wounds. Since he wasn’t physically wounded her powers didn’t work on him so he wasn’t waking up. They had no idea what was wrong with him.
'couse she couldnt heal him(wake him up), she thought they had lost her son again , and she got scare, i think?
*im not good at english, if i dont make sense sorry
Spoiler
His mother actually has a truama from her past which makes her fear healing others. The person she tried to heal in the past died and she blames herself for the death and hence she cant properly use her power to heal
was his mother scared of him or scared for him cause I don't get the scene when she healed him.