It's hard to know if they're OK when it's crappy outside, I know. They just feel blah like we do.
The baking soda drench is just baking soda mixed with water. Everyone's ratio is different. I don't really measure out the baking soda; I just make a solution that's enough to get the baking soda liquid enough to go through the syringe. If it's too pasty, try adding a little more water.
As time goes on you'll learn their personalities and know if they're "off" or not. For now, just keep an eye on her and love up! They sure are cute!