Firstly: Welcome Aleu45, I can see this is your first post.
Secondly: I think Balto remembers his mother (in fact he tells Aleu that his mother was a white wolf), but he cannot remember her name. If you mean that Aniu isn't the same White Wolf from Balto 1, since he wouldn't have told Alue he remembered almost nothing about his mother when he actually saw her after his fall while carrying the medicine to Nome, I personally prefer to think they are the same wolf. This is just my opinion. But, if I'm not wrong, Phil Weinstein wanted that Aniu was the same White Wolf of Balto 1.