awwwww i hope that person who came was her mother (╥﹏╥)

I want to believe that it was.
If you look at the sleeves, the one showed on the last page kinda resembles the one on the first page. Also, like on the very first page, the last page also gives us the imagery from the mum's pov. With the hand opening the door and the picture depicted from a third person's eyes, given the fact that these were the only two times we get to see what the character who's out of the frame is thinking, I think the author wants to show that the mum returned.

I may be reading too much into it, but I really do hope that she came back as well.