I'm Beth, Iv' been playing since July 2019, not a long time at all, and I've tried a few champions, and even some off-meta ones in the Support role, but I found this build online and have modified it, updated it with some help from the Sona Mains discord. And I think I am at 80% Win rate on this build right now, not bad for a noob I guess. I would love to see it in more capable hands.

At the start of the game, your aim is your help your ADC farm, as we aren't prioritising on healing (your W uses so much valuable mana in the early game, and we aren't buying Mana items) we are going to be saving your W for emergencies or if you areu full of mana.

My philosophy for this build is, instead of simple healing the damage done by enemies to your ADC, you prevent them from doing damage in the first place by gaining the power to prevent and kill them before they can, until the point they realise you are too dangerous to risk farming themselves.

After you and the ADC has taken the first tower you can both start roaming, you don't technically have to stick with them all the time, but see who needs help pushing another tower in getting the three outer towers really helps as it limits the safe space the enemy has on the map.

Focus on enemies that are focused with an ally, they will be vulnerable to die in a couple shots. Run in, hit them with your Q, W your ally and keep a safe distance, as you are an easy target if you don't kill them first. you don't do long fights, you need to kill them to get your mana back.

Continue warding the enemy jungle to prevent their usable space even more, helping you get objectives considerably.