LOS ANGELES (Reuters) - Lady Gaga towered over other female musicians in 2011, heading a list of top earning women with an estimated $90 million in income, according to a Forbes.com survey released on Wednesday. The Born This Way singer and performance artist made more than double her nearest rival country/pop artist Taylor Swift thanks to multiple endorsement deals and an estimated $1.3 million nightly gross ticket sales from her concert tour. Swift earned about $45 million, thanks to her hit album Speak Now, perfume line, and other deals, just ahead of Teenage Dream singer Katy Perry with $44 million. Forbes.com drew up its list from data on pre-tax income compiled through record sales, touring data and interviews with music lawyers, managers and concert promoters.