The April 28, 1806 journal entry does mention Sacajawea and here is the appropriate part.
"Fortunately thee was among these Wollawollahs, a prisoner belonging to a tribe of Shoshonee or Snake Indians, residing to the south the Multnomah, and visiting occasionally the heads of the Wollawollah creek. Our Shoshone woman, Sacajawea, though she belonged to a tribe near the Missouri, spoke the same language as this prisoner, and by their means we were able to explain ourselves to the Indians, and answer all their inquiries with respect to ourselves and the object of our journey. Our conversation inspired them with much confidence, and they soon brought several sick persons, for whom they requested our assistance. We splintered the broken arm of one, gave some relief to another, whose knee was contracted by rheumatism, and administered what we thought beneficial for ulcers and eruptions of the skin, on various parts of the body, which are very common disorders among them. But our most valuable medicine was eye-water, which we distributed, and which indeed, they required very much: the complaint of the eyes, occasioned by living on the water, and increased by the fine sand of the plains, being now universal."
As can be seen in this example, the person becomes secondary to the acts. Her translation abilities had helped the Corps on more than one occasion but the person doing the translating is hardly important enough for the captains to mention. It is most unfortunate because we have so many questions about Sacajawea the person.