Ruth Powers is the Simpsons' next-door neighbor and the single mother of Laura Powers.
Ruth is divorced and she has a daughter named Laura Powers, who no longer lives with her. The circumstances behind Ruth's marriage are not explained, but she has mentioned her ex-husband behaves similar to a hard working and career dedicated but less affable version of Homer Simpson and he was continually stiffing Ruth on child support. Due to his faults that were said to have lead to their messy divorce, Ruth claims he stole her youth and outlook on life, which includes her becoming a near misandrist that she stole his car for revenge. 
Ruth and Marge Simpson became fast friends after Ruth moved in next door. One evening, they went to a ballet after Homer, who was originally supposed to go with Marge, literally got stuck at work (with his arms in two vending machines). Later they had a girls' night out where they went line dancing at a country bar called Shotkickers, went raving at an underground club named The Hate Box, did some target shooting (using a farmer's antique cans as targets), and went up to the Springfield sign overlooking the city. They ended up going on the run from the law, however, after Chief Wiggum tried to pull them over because of a broken taillight, and Ruth chose to flee because they were driving the car which she had stolen from her ex-husband. One possibility for she not getting any punishment from stealing the car is that her ex-husband didn't give any money even though the court demanded it. Finally, the auto theft charges against Ruth were dismissed, undoubtedly due to the fact that Lionel Hutz was representing her ex-husband.
Ruth had shown signs of being an alcoholic, since she is seen at an alcoholics anonymous meeting in Simpsons: The Movie, as well as watching a video on the results of drunk driving with a horrified expression on her face in "Duffless". She was also at Moe's Tavern in New Kid on the Block when Moe started calling out for "Ivana Tinkle", with her clutching her mouth in an obvious attempt at restraining her laughter upon his first calling out the name, implying she immediately realized Moe was being duped.
After her appearances of New Kid on the Block and Marge on the Lam, she and Laura had moved out of Evergreen Terrace sometime in the decade of her next appearance and she was was later imprisoned for a short time during this for another offense, which is unspecified. While she was in prison, Ruth built up her muscles and became a bodybuilder, which earned the title "Miss Mexican Mafia" and took steroids to expand her muscles.  Noticing her old neighbor while on a jog at Springfield's muscle beach and pier, Marge reunited with Ruth where they shared their interests in bodybuilding and where Ruth introduced her to taking steroids. Later in The Simpsons Movie, Ruth was shown joining the angry mob that attempted to kill Homer, and possibly the other Simpsons, for getting the town sealed in a dome.