。
The moment she heard that, she came right here.
Literal
She [topic-は] that [object-を] hear [as-soon-as-や否や] right-away here [to-へ] came.
~や否や (yainaya) is a literary, somewhat formal conjunction meaning 'as soon as, the very moment that.' Built from や (a classical exclamatory) plus 否や ('or not'), suggesting a kind of breathless temporal joint — 'no sooner had X than Y.' Compare with the everyday ~とすぐに ('as soon as') and the more vivid ~た途端 ('the very moment') — ~や否や sits at the formal end of this family. Pairs naturally with すぐ ('immediately') as here, doubly underscoring the speed. Mostly seen in written narrative, news, and formal speech.