In the previous circumstance in which Haman asked his family and friends for advice (Esther 5:10), he had to summon them. According to Ibn Ezra, Haman did not need to call for them now because, after having recommended hanging Mordechai and going to Achashverosh, they stayed around to see the results of their advice.
The M’nos HaLevi suggests that they had left, but returned to comfort Haman upon death of his daughter and the other terrible events of the day. He also writes that Haman only told Zeresh, but word spread.
The Talmud (Megillah 16a) says the verse describes Haman as mourning his daughter because she threw the waste in her chamber-pot down upon him from the roof, thinking he was Mordechai, and then jumped from the roof when apprised of the reality.
R’ Mendel Weinbach explains that Haman’s daughter had the pot because she had irritable bowel syndrome (IBS) in order to lose Achashverosh’s contest to find a new queen.
According to the Ginzei HaMelech, the verse repeats that Mordechai adopted Esther because Esther acted like a daughter, obeying him the way a child should without rebellion.
According to the Malbim, this verse is emphasizing that Mordechai’s raising Esther meant that he educated her, in the sense of Rav Shlomo Wolbe’s theory of planting and building. A parent or a teacher has the dual role of physically planting ideas, but also building with the child’s potential. Perhaps such an idea can be used to explain why Avichayil is mentioned in this verse. He literally planted Esther, and Mordechai built upon her potential.