"We tried to tell her, but she was not there."
Translation:ניסינו להגיד לה, אבל היא לא הייתה שם.
The word form היתה appears in the Tanakh and is conventionally used with niqqud/nikkud. It's orthographic/spelling variant הייתה appears in the tips and notes for this Hebrew skill and is apparently conventionally used without niqqud/nikkud (especially today[?], although similar spelling variants and the use of 'matres lectionis' appear in ancient times as well, including the Dead Sea Scrolls or, alternatively, the Judean Desert Scrolls). The difference is merely one of orthography/spelling.
As I recall, the notes for this lesson don't make clear if they should both be regarded as correct. This translation exercise, however, assumes that they are indeed both correct. At the very least, the course contributors probably wanted us to be familiar with both forms. Maybe someone else can offer further confirmation or clarification.