She wanted to be alone.

Her mind was in a state of flutter and wonder, which made it impossible for her to be collected.

She was in dancing, singing, exclaiming spirits; and till she had moved about, and talked to herself, and laughed and reflected, she could be fit for nothing rational.
Her father's business was to announce James's being gone out to put the horses to, preparatory to their now daily drive to Randalls; and she had, therefore, an immediate excuse for disappearing.
The joy, the gratitude, the exquisite delight of her sensations may be imagined.

The sole grievance and alloy thus removed in the prospect of Harriet's welfare, she was really in danger of becoming too happy for security .-- What had she to wish for?
Nothing, but to grow more worthy of him, whose intentions and judgment had been ever so superior to her own.
Nothing, but that the lessons of her past folly might teach her humility and circumspection in future.
Serious she was, very serious in her thankfulness, and in her resolutions; and yet there was no preventing a laugh, sometimes in the very midst of them.

She must laugh at such a close! Such an end of the doleful disappointment of five weeks back! Such a heart--such a Harriet! Now there would be pleasure in her returning--Every thing would be a pleasure.