Hit Lady (1974)

Sinopsis: At a Texas barbecue, a pretty woman chats up a wealthy rancher, and soon they're off on a horseback ride. Before she shoots him on an isolated road, she gives him a minute to reflect on who he might have offended on his rise to the top. She's Angela de Vries, a contract killer based in L.A. She wants this to have been her last job; her contractor wants one more death, a national union leader, made to look like an accident. She starts her homework on this mark. Meanwhile, in her private life, she's in love with a budding photographer. Is there any way that she can get out of the game and have a full love life?