your baby’s sleep at 6 months old is as important for her health and development as it has been since she was born. This is because it gives her the energy to get through these days that are full of growing and developing and trying new things. It's also important because how she learns to sleep now could affect her sleep patterns as she grows up.
She needs somewhere between 12 to 14 hours of sleep in a 24 hour period, and most of those hours (10 to 12 of them) should be happening at night, as your baby is at the age when her circadian rhythms are establishing themselves. The rest of those hours come in the form of two to three naps spread throughout the day.
If that ideal isn’t happening for you and your baby naturally, there are a few ways to start to nudge her sleep patterns in that direction. First, your baby should start to figure out how to put herself to sleep, and if she is falling asleep while being held, say, she may not be able to fall back asleep on her own. One common way of keeping babies from relying on their parents to be able to fall asleep is for parents to make sure to put their babies down to bed when they're sleepy but still awake, so that they're more used to falling asleep without the comfort of their parents' arms.
Another way to encourage sleeping through the night is to keep the room quiet and dark during night time feedings or diaper changes. If your baby wakes up in the middle of the night but isn’t hungry and doesn’t need a diaper change, soothing her back to sleep in her crib quietly in the dark will reinforce the idea of the difference between night and day. At the same time, letting her nap somewhere that she can see the sun, instead of in the dark will help to reinforce her circadian rhythms, and can help with night-time sleep.
If your baby is getting too much sleep during the day, shifting her afternoon nap gradually earlier in the day may help. Cutting down on naps may feel like a good way to encourage a full night’s sleep, but may actually have the opposite effect--an over-tired your baby could actually have more trouble falling asleep.
This is an active time for your baby, and separation anxiety, teething, or even just a little cold can be enough to throw her sleep schedule off-kilter, but she is working her way through to a regular sleep schedule. The time you put in establishing that will only help you in the future.