Why didn't Rita go to Frank's dinner party?

What I

think is that didn't want to go to the party because the fact that she migth have share the whole dinner with people who would have anything in common either to share and to talk with Rita. And because she wuold have the opportunity to compare herself with those people in the party.What's more,she might have felt she was not at the same level. She probably felt like a kind of test and she was not ready for this. Frank tells her that he wanted her to be there. He says that people at the party would have seen her as someone funny, delighful and charming... When Rita listensto this, she feels really awful and bad. What she wants is not to be funny, she wants to be taken seriously and be able to take part in their seriuos conversations as if she were one of them. She says: 'I don't wanna spend the night takin' the piss, comin' on with the funnies because that's the only way I can get into the conversation...'

Her mother's words reflects the same feeling that Rita has,because she has no opportunty to leran at some moment in her life.I think these words made Rita encourages to go on and not to have the opprotunity to regret not making the effort to improve herself.