The narrator describes Mrs. Samsa's response to seeing her son, after his metamorphosis:
His mother——in spite of the manager's presence she stood with her hair still unbraided from the night, sticking out in all directions -- first looked at his father with her hands clasped, then took two steps toward Gregor, and sank down in the midst of her skirts spreading out around her, her face completely hidden on her breast.
Her first reaction, then, seems to be one of utter disbelief. Mrs. Samsa appears to look to her husband for confirmation of what she is seeing. Then she seems to feel an impulse to go to her son, to comfort or assist him in some way, but before she reaches him, she sinks to the ground, indicating that she has lost hope. Her head is down, and this particular posture tends to imply dejection and sorrow.
A little while later, during this same interaction,
she, who had seemed so completely self-absorbed, all at once jumped up, her arms stretched wide, her fingers spread, and cried, "Help, for God's sake, help!" held her head bent as if to see Gregor better, but inconsistently darted madly backward instead; had forgotten that the table laden with the breakfast dishes stood behind her; sat down on it hastily, as if her thoughts were elsewhere, when she reached it; and did not seem to notice at all that near her the big coffeepot had been knocked over and coffee was pouring in a steady stream onto the rug.
It is obvious that Mrs. Samsa feels either herself, her son, her family, or all of them, to be in need of help, perhaps to know how to deal with her son in his terrible new condition, but it is not totally clear who she expects to help them. The manager? That seems unlikely. It appears that she is still attempting to understand what Gregor's new state actually is, but, at the same time, she is so horrified and frightened by what she sees that she cannot help but run away from it. She has forgotten her breakfast and doesn't seem to notice anything else that is going on around her. It seems a lot like disbelief and horror.