She may be extra hungry due to a growth spurt.
or
she may have an ear infection
or
she may have started being colicky
or
It may be that you are missing her cues for being sleepy. Once a baby gets overtired they get so wound up they can't sleep. It gets beyond their ability. Try these methods and see if that helps:
try using the Baby Whisperer's EASY method for a schedule, and the Happiest Baby on the Block 5 s's method. Those two combined will make cio not be a needed thing (at that age)
EASY - when the baby wakes up it Eats. After you feed it, then it has Activity - bouncy seat, tummy time, sitting up and playing with toys, swing, exersaucer, etc. When the baby gets fussy check the B's - boredom, butt or burp. If it's none of those then off to Sleep. Don't wait for the baby to do more than get the tiniest bit fussy, then see what is causing the fusses - if it's just that they needed their diaper change do that, but if it's not the activity is boring, the butt is dirty or they have to burp, then put them down. This may happen after as short as 45 minutes, don't freak, it really means they are tired.
Now, to get them to sleep use the 5 s's. Swaddle the baby, hold the baby on their side and sway as they suck on something (paci, your knuckle or their finger/thumb) and make a shush noise. This will calm your baby. When the baby is calm, but not asleep yet, keeping them swaddled lay them in the bed. I like to pat them instead of sway after a minute or two cause you can still pat after they are put down but you can't sway, so pat the baby and continue patting gradually decreasing it as you put them in the bed. Also continue the shushing as you put them down, again gradually getting quieter.
If you do these two you will find a well rested, easily managed baby in no time.
N.