。
She was in a great hurry.
Literal
She [topic-は] terribly was-hurrying.
急ぐ ('to hurry') conjugates as a normal -u verb, and 急いでいた is its past progressive — 'was in the middle of hurrying.' Note that the speaker is reporting an observation; in everyday conversation the speaker about herself would more likely say 急いでいた without ひどく, or use phrases like 大急ぎで ('in a great rush'). The combination ひどく急ぐ ('hurry terribly') reads as elevated narration rather than casual speech.