The Martins were particularly kind to Harriet but I disagree she had any design in it. Harriet “said how fond she was of ” walnuts rather than expressed a desire for them and I think much the same happened with Mr. Martin asking the shepherd’s son to sing to her—I think it is likely he or his sisters drew the information from Harriet and then did what he could to be particularly obliging.

Harriet was not insensitive to the loss of Abbey-Mill Farm or its inhabitants. After Harriet rejected Mr. Martin she was concerned that he and so his mother and sisters would be unhappy. She was also “so anxious that they [his mother and sisters] should not fancy her ungrateful” (7) and “I shall never be invited to Abbey-Mill again," was said in rather a sorrowful tone” (7).

Harriet also received a great deal of special treatment from Miss Woodhouse. Emma polishes her up, flattering her and even paints her portrait. I am sure Hartfield is a wonderland to Harriet. First the Welsh cow may be called hers (4) and then a bedroom fit for a gentleman’s daughter (8) as well. I think Harriet feels gratitude for the attentions of Hartfield and Abbey-Mill Farm.

It seems to me Harriet is under Emma’s influence as nearly as much as a person can be and I don’t think she ever had enough enough time away from Emma before the proposal to be free of her influence:

Harriet Smith's intimacy at Hartfield was soon a settled thing. Quick and decided in her ways, Emma lost no time in inviting, encouraging, and telling her to come very often… a Harriet Smith, therefore, one whom she could summon at any time to a walk, would be a valuable addition to her privileges. (4)

Emma questions Harriet closely about Mr. Martin and the next day they meet him on the Donwell road. In Ch. 6 Harriet appears to spend most of the day at Hartfield (see link). It is the day Emma begins her portrait of Harriet and she was to “sit again the next day… the same success and satisfaction… accompanied the whole progress of the picture” (6). By the day of the proposal it seems to me Harriet is at Hartfield constantly, perhaps daily:

Harriet had been at Hartfield, as usual, soon after breakfast; and after a time, had gone home to return again to dinner: as she returned, and sooner than had been talked of, and with an agitated, hurried look… (7)

Harriet spends “more than half her time” (8) at Hartfield. I think it is safe to suggest a significant portion of Harriet’s time at home is passed in sleep and beyond the influence of anyone. Additionally for weeks Harriet has been staying overnight at Hartfield, this has been so frequent that a bedroom may be called hers. The sleepover to moderate Harriet’s regrets of Mr. Martin turns into a visit spanning some days:

Harriet slept at Hartfield that night. For some weeks past she had been spending more than half her time there, and gradually getting to have a bed-room appropriated to herself… She was obliged to go the next morning for an hour or two to Mrs. Goddard's, but it was then to be settled that she should return to Hartfield, to make a regular visit of some days. (8)

Emma suggests “Harriet must give us as much of her company as she can while my brother and sister are here” (9). Another example of the amount of time they are together is to be found in Harriet’s attending Emma on a “tolerably regular” (10) exercise schedule. I don’t see when Harriet was away from Emma long enough to be free of her influence.