There may be a couple of reasons for this:
1. She is a newborn and this is completley normal (welcome to motherhood) babies do not sleep in circadian rhythm until about 4-6 months of age.
*what you can do- nothing just wait it out, it wont last forever, know that in a year she will be walking and sleeping alot more (how much sleep, who knows but more is better) she will be older before you know it enjoy her cuteness and smallness while you can. I know, I have two daughters one 4 weeks and one 20 months, I am enjoying my second a whole lot more because I know how fast it goes.
2. Since you are breastfeeding she is probably going through a growth spurt and needs to suck on your breast (all the time) which increases your milk supply.
*what you can do about it - keep her up as much as possible during the daytime, keep the lights on while she sleeps, don't let her sleep more than 2 hours without waking her up. She can go back to sleep, but wake her up and break the sleep cycle. Then at night breastfeed as much as possible, the key is to fill her up like a thanksgiving meal before she goes to sleep. Keep her sleeping upright, you can buy things she can sleep on to keep her at a slant.
Or you can sleep with her in your bed, buy a co-sleeper or just have her sleep next to you, just be really safe, dont sleep with blankets on you and keep your pillow away from her head and face and get a gaurdrail for your bed. Check out co-sleeping online, I slept with both of my daughters it works great!!
3. She has colic and digestive issues, newborns have very sensitve digestive systems.
*what you can do - massage her rectum area, give a warm bath and massage her belly area gently to stimulate poops and toots! Her gas causes her pain so help her.
4. she is adjusting to life outside the womb (a womb wich was tempature regulated and cozy and safe and not so noisy.
5. it is somthing you are eating that is causing her to be a bit gassy.
Figure out what it is if you want to take the time and elimanate it from your diet.
Last,
just enjoy the time you have with her, and know this wont last forever, it gets better, (way better) with time.
Have fun!