D..
Do you have a crib? Has she ever slept in it? Where is she sleeping now?
If you do have a crib, and she has never slept in it, it will be hard, but it's doable. It will take at least a week (maybe 2). Decide that you are willing to stick with it no matter what - don't try unless you are really willing. And do it before she learns to stand up - it will make it easier.
Put her to bed in the crib. She will cry. Sit on the floor beside the crib, and put your hand through the slats and stroke her leg. She will still cry, but she will know that you are there. She will eventually cry herself to sleep. Leave the room. She'll probably wake up in the middle of the night. Do the same thing. Don't talk to her, don't pick her up. Don't feed her. She doesn't need formula or breast milk now at 6 months. She might WANT it, but she doesn't need it. If you haven't already night-weaned her, do it now at the same time.
What you are having to do is teach her to self-soothe. She hasn't had to do it before, and it's hard. It will be hard for you too because you won't get much sleep for a while. But the payoff is that she eventually will stop waking often, and you will stop going in. She will cry for a while and then stop. And then she will stop waking up. And you will all have some good sleep.
Be 100% consistent, or don't do it at all. 100% consistent means no picking her up and no talking to her, period.
I would not try it with naps during the day until you have the nights completely handled.
Good luck,
Dawn