Mirko isn't the only character in the My Hero Academia universe to be born on March 1st.

How tall is Miruko?

As a fully grown woman, Rumi Usagiyama stood at five feet and two inches tall. Her red eyes were tilted slightly inwards and her long white hair flowed freely down her back to her waistline.

How did Mirko lose her arm?

In My Hero Academia chapter 262, Mirko lost her left arm during a fight with five Nomus. Three of them are still standing and she might be able to survive through them. However, things will be different once Dr. Ujiko finishes waking up Tomura.