Выберите правильную форму глагола So when she announced she _____________ (would learn/will learn) to box professionally,

The answer is here : 

So when she announced she would learn to box professionally, there was nothing her parents could say to deter her. She said she just loved how it feels.

В тексте говорится о прошлом , в связи с этим использовано время Past Simple Tense