She's hungry.
6 months is a growth-spurt time... and in conjunction with that, it is also a time of TONS of developmental changes and hitting milestones. So there are MANY things going on in a baby at this age. It does tweak their sleep.
You need to feed on-demand. Intake has to keep pace with them & their growth, which you cannot control.... hence eating every 2 hours. Every 2 hours is not a lot... because, when a baby is growing, they ALSO go through what is called "cluster feeding" in which a baby even feeds every.single.hour.or.less.
BOTH my kids did that as babies. I breastfed. It is arduous. That is how it is.... .especially when baby is hitting growth spurts and developmental changes.
It is real hard to "make" a baby sleep or longer. Because it is reflecting a baby's natural growth patterns and intake needs and physical/cognitive changes. We cannot extinguish that.
Some do crying-it-out at this age...but he is too young for that and I really don't believe in that method. :) And people mostly do it because they don't want baby to wake anymore. Which is really not natural if a baby is having growth-spurts etc.
Maybe have Hubby get up and feed her?
Are you breastfeeding? If so, you also need to make sure you are producing enough milk? if not she will always be hungry.
Is she latching on properly? If not, she will not be getting enough intake, either.
ALL through babyhood... sleep is NOT static nor finite and it ALWAYS changes. A baby, much less an adult, does not sleep the same throughout their life.
ALSO, it could be teething.
Or separation anxiety as well.
MANY things at this age, which comes up. We cannot stop their development or hunger/growth spurts.
Have a consistent daily routine everyday... for naps and bedtime. At this age they typically take 2-3 naps per day. Over-tired kids do.not.sleep.well nor fall asleep well, and they wake more. They actually sleep worse at night. So naps are very crucial.
Just some reasons that at this age, affects a baby.
It is really normal and typical.
It changes all the time.
She is hungry. She needs to eat.
all the best,
Susan