In act 3, Why and what are the reason for Mrs. Higgins' impatience with her son and Colonel Pickering?
In chapter 3 of the play Pygmalion Mrs. Higgins is "at-home", which means that it is a day to expect and receive visitors
As Henry Higgins enters his mother's house uninvited, his mother reprimands his entrance because his behavior is so rash and improper that none of her friends what to visit when they find out that Higgins is there.
However, the reason behind his visit is to tell his mother about the Eliza project and to tell her that Eliza will be visiting.
Later on, after a visit from the Eynsfords and Eliza's entrance, Mrs. Higgins begins to lose patience with her son's plan with Eliza. First, she notices that Eliza's project does not really come to a full closure: She is only expected to act correctly for a specific event. Nobody thinks about Eliza once the plan of Higgins and Pickering is fulfilled. Mrs. Higgins is perhaps more angry at her son's inherent careless nature more so than Eliza's fate.
Second, she is also upset at that Pickering is in on the plan and relate to Mrs. Higgins things that he finds interesting in Eliza. With horror, Mrs. Higgins has to admit to herself that her son and his friend are a pair of inconsiderate men who could care less about the fate of a woman whom they have obviously used for their own benefit.
MRS. HIGGINS:No, you two infinitely stupid male creatures: the problem of what is to be done with her afterwards.
HIGGINS:I don't see anything in that. She can go her own way, with all the advantages I have given her.
MRS. HIGGINS:The advantages of that poor woman who was here just now! The manners and habits that disqualify a fine lady from earning her own living without giving her a fine lady's income! Is that what you mean?