Nine Month Old Suddenly Waking up in the Middle of the Night?

Our son did that, and I let it go on WAY too long. Months. At last I tried shorting his bottle by 1/2 oz. each night, so he eventually got about an ounce and then gave it up. He still whimpered at the same time each night for a few nights, but then slept through again. He actually started it up again much later (almost a year later?) and I started up with the milk again so that we could get some sleep and then realized the error of my ways and started diluting it w/ warm water until all he got was water. You might try thinning out your breastmilk or formula a bit at a time to see if she changes her mind about sleeping through.

I bet it's just a phase. My son went through sporadic phases like this. Once, he didn't sleep for more than 20 min at a time for a week (which, of course, happened to be finals week.) He's 2 1/2 now and he sleeps like a champ. Give it another week or so.

9 mos. is also a key time for separation anxiety... just be thankful you are getting sleep. both of my kids have sleep issues... it's been 5 years since i slept well. it could be worse...

I'd say a baby that has slept thru the night from 8 weeks to 9 months, is a blessing! None of my 3 managed to sleep fully thru the night until much older.Babies don't come with a sleep guarantee. Being up once a night is not uncommon, for well beyond 9 months. Perhaps if you responded sooner, it would be easier as she either grows out of this, or doesn't.

If you are already giving her a bottle try an ounce of prevention. About an hour and a half after her dinner of cereal (rice cream is best) give her the bottle with a banana as a smoothie. You'll have to use a hot needle to make the opening of the nipple larger. She'll be full and sleep through the night.
If you go to bed early don't expect her to sleep a full night until morning without food. Babies have a very high metabolism.