Sona vs Nami

How do I out harass her?

She doesn't need to aim anything other than her ultimate. She can just press Q and even if I have positioned myself away from my ADC it hits both of us.

Unless I catch her in a bubble she isn't going to die. She gets MS from her E and usually gets Lichbane which also makes her fast. I would say Nami is a bad match up into her but I haven't had any luck with any other healer or Mage supports. A tank support works but only if the Sona player is bad and eats every Solar Flare or Glacial Fissure to her face.