Learning to Speak

In Act III of Pygmalion, Eliza is presented to Mr. Higgins' mother and is reuntied with the people she had met earlier at Covent Garden. I don't understand this act all that well, for I don't know why Clara, Freddy and Mrs. Eynsford Hill show up so randomly at Mrs. Higgins' place.Something I found ironic was how at the same time Higgins is working to get Liza to speak well, Clara tries very hard to update herself, and her mother for instance,on the latest form of slang.She says she finds it old fashioned that someone should carry themselves the way her mother does, and thus speaking the way she does