What evidence is there that says a woman must make up fasts she has missed due to her period? Isn't it similar to salaah where she is not required to make up for any namaaz she has missed?

1. Moaadhe Al- Adawiyya narrates that she inquired from Ayesha (
radiyallahu-anha ) the reason a female in menses makes qadha (make-up) for
her missed fast but does not do so with missed salaah during menses. Ayesha (
radiyallahu-anha ) replied that we were ordered to make qadha for the missed
fast during menses and we were not ordered to do so for missed sallah(Mishkat
-vol. 1 p.178-Thanvi)

2. Ayesha (radiyallahu-anha) states that she used to have missed fasts on
her and she could only fulfill them in Shabaan. (Ibid)

And Allah Ta'ala knows best

Mufti E.Desai