What is the time statute of limitations for malpractice suits?

my mom ped in August 2009. I am wanting to find out if I have a legitimate legal malpractice suite against her doctor for not reading labs for an entire month, which ultimately set her in the downward spiral in her health. also leading her to spend three weeks in the hospital undiagnosed, and another two week stent in the hospital, with her demise of a stroke.