Family and Situation
Mrs. Phillips was born Miss Gardiner, the daughter of Mr. Gardiner Senior and sister to Edward Gardiner and Mrs. Bennet. She married her father's clerk, a Mr. Phillips, and may well live in her childhood home in Meryton, Hertfordshire, as her husband is now running her father's business.
In the novel, we're never told of her having children of her own, but she entertains her Bennet nieces - particularly Lydia and Kitty - with some frequency. The narrator tells us that she has put her nieces' "indifferent imitation of china on the mantlepiece" in her home, suggesting great affection.
Character
Mrs. Phillips seems eager to create opportunities for her Bennet nieces to mingle with officers and other young men, even going so far to yell a them through a window in Meryton to try to get them to invite the young men into her parlor, suggesting that she can be as crass as her sister Mrs. Bennet. On the other hand, Mr. Collins thinks Mrs. Phillips is very elegant and condescending.
At one point, Mr. Phillips is described, from Lizzy's point-of-view, as “broad-faced, stuffy" and "breathing port wine.” Presumably Mrs. Phillips either merely tolerates this behavior or keeps apace.