All I can really say is take a tylenol for the headache and remind yourself that she is just one year old. As you alluded to and as somebody else mentioned, it is very common because they cannot communicate very effectively with words yet, so screaming is one way that they find gets a message across. Responding calmly with a quiet voice and a finger over the lips saying "quieter voice please" helps to remind kids when they are being too loud, especially if that becomes a consistent reminder. Though, I also am an advocate that kids do need time to be loud. I often would find people telling kids to be quiet outside on a playground as if they are to use an inside voice while outside. To me, a playground is where it is surely appropriate for them to yell and play all they want and explore that loud voice they all love to make or at times inside when nobody is napping I think they should be able to play loud games and what not as it is part of being a child and exploring their world. It seems like not until elementary school (and even then they forget), do they really have the distinction from when they are being loud vs. a regular voice. I joke that there are two sound levels with the kids...loud and sleeping. :) With your daughter being just 12 weeks old, don't be surprised if she's the same way when she gets to be that age. Having worked with kids and their parents for years, it's amazing how often parents are driven crazy by a developmentally appropriate characteristic of another child, come to find their child develops the very same trait. As annoying as some of the toddler traits can be, I've seen a lot of feet in the mouth that way between things like biting, hitting, thumb sucking, whining, etc. Kids will be kids, so hang in there, it's a phase that will lessen and lessen as she develops a bigger vocabulary, though it does take a while, but you'll have relief when she goes back home. :)
