I would be very careful about switching formulas. The soy milk won't help with congestion and could upset her tummy!
The best thing that I have found for congestion, since they took infant cold medicine off the market is to sit and play with her in the bathroom with the shower on as hot as it will go to get steam going - obviously keep her away from the water, but the steam is great. Then keep a cold air humidifier in her room for a couple of days and brace yourself for earaches :)




