Toni is too BIG

Everybody is missing the point here (or maybe needs glasses). Harriet in the book might have been plump, but that does not bar her from being dainty, which is a matter of manners as well as appearance (and plump women often have small, dainty hands and feet). Toni Collette is not merely not thin--she is clumsy and coarse. She knocks things over. She is a slow thinker. Her mouth hangs open when she is perplexed. This is not charming or feminine, and it certainly isn't classy. Also, if being plump was so desirable, how come all the clothes that have come down to us from that period are so tiny and the portraits of female aristocrats show them to be thin? It is true that plumpness was in the past desirable because it showed you had enough to eat, but among the upper middle class and certainly the upper class it was not a consideration because it was taken for granted that you had enough to eat. Also, it was more of a factor with men than women, because plumpness made the man look respectable and a good provider.

lol...probably a grain-the one Emma ate-in that.

I don't recall that Mr. Knightley ever says or implies any disapproval of Harriet's being a bastard. Harriet's status is discussed because Knightley is trying to illustrate to Emma how she has ruined Harriet's best chance for marriage that she is ever likely to receive. Additionally, Knightley's purpose is also to make clear to Emma that Elton would never consider Harriet because he would never consider anyone who is a bastard. Emma deludes herself into believing that this won't matter to Elton; Knightley tries to set her straight about it.

Knightley's initial objection to Harriet is his conviction that neither woman will do the other any good. Knightley would rather see Emma keep company with someone whom he thinks will guide Emma in a better direction (reading, practicing her pianoforte, etc.). He doesn't think Harriet is a good candidate for having this kind of positive influence over Emma. He's convinced that Harriet will go along with everything Emma says, and that as a result Emma will believe she already knows everything she needs to know, and that she'll become even more self-important than she already is. Additionally, he's worried that Harriet will develop ideas and airs which will prevent her from successfully mixing with people from her own station.

I think her the very worst sort of companion that Emma could possibly have. She knows nothing herself, and looks upon Emma as knowing every thing. She is a flatterer in all her ways; and so much the worse, because undesigned. Her ignorance is hourly flattery. How can Emma imagine she has any thing to learn herself, while Harriet is presenting such a delightful inferiority? And as for Harriet, I will venture to say that she cannot gain by the acquaintance. Hartfield will only put her out of conceit with all the other places she belongs to. She will grow just refined enough to be uncomfortable with those among whom birth and circumstances have placed her home. I am much mistaken if Emma's doctrines give any strength of mind, or tend at all to make a girl adapt herself rationally to the varieties of her situation in life.—They only give a little polish (ch. 5).