I'd take a hard engage tank, personally(Leona, Alistar, Thresh, Blitz). Not that I really play support, but reasoning would be that Sona is squishy. Like real squishy. Like the squishiest. A support like Leona can jump on her and your ADC can delete her in no time flat. My counter to her poke is usually just to punish her the moment she gets in range to poke. She walked up to Q? Lock her down and kill her.
I could imagine into a Sona/Luc, or some similar early game ADC, that it could backfire... But in general my goal with Sona is just to make it scary for her to even step close enough to poke.
But like I said, I don't really play support much. Just my thoughts from the little bit I do play it.