When I say “so top,” I mean: I will take the loneliest lane and I will win it. Not because I’m strong. Because I have no choice.
The phrase "I don't have a mother anymore" is not necessarily a declaration of death. In Japanese emotional subtext (which gets lost in English patches), it is a declaration of . It is the moment Ichika realizes she must become her own protector, stepping into the "motherly" role for her own friends because the person who was supposed to guide her is gone.
The phrase draws on the intense storyline involving Mafuyu Asahina’s domestic situation: The Mother Conflict
Because several prominent characters share the name Ichika, the context of this quote varies across series: Ichika Nakano