Plat JG here-
There is only one question you should ask yourself before you gank- If you gank, are you positive you'll get a gank or blow a summoners?
If the answer is "no", then don't gank. Soraka is played either passively as a healbot, erasing damage while ADC farms with a stalled lane, or she is going to be aggressive and push them back into their turret.
If your Soraka had any brains, and if your ADC had any brains, they'd stall the lane in front of their turret for the whole early game and let you come in to gank. Then if that happens, if your Soraka had any brains, she'd land a clutch silence-root to lock them down while you and the ADC do their dirty business.
Once again, before ganking, ask yourself: "If I gank, am I positive to get a kill or blow a summoners?"
If no, then farm/go somewhere else.
The only time you should intervene in another lane when you answer a "no" is if they got a 4 man gank and you need to make your presence known so they don't get a turret. You're not there to serve them. You got 3 lanes and a JG you keep your eye on, you don't bend the knee whenever it's convenient.