Hi there and welcome to BW!
We are opposed to CIO on this site as it can break the bond of trust between you and your LO, so no worries there. Here are a few links that are very informative on that.
Research on why 'cry it out' and 'controlled crying' is NOT recommended!Cry it out (CIO): 10 reasons why it is not for usKara & Alexandra's StoryIf you are desperate to let your lo "cry it out"...read this firstAt her age, since she's not been an independent sleeper, your best approach will be Gradual Withdrawal. Here is a link with some good details (starting about half-way down):
Walk In/Walk Out vs. The Gradual Withdrawal Method (HOW TO CHOOSE) Basically, you will be in the room with her to fall asleep and then over a week or so, work your way out. You'll want to use your voice as much as possible, as she's able to understand a lot of what you say, and you'll want to remove your arm and have her retrieve her own dummy. If I were you, I'd just set up a mattress on her floor for now and camp out there, so that you don't have to be in and out in the MOTN and you can at least rest lying down. It will likely be a difficult few nights, but she will learn quickly at this age and it will be worth it!
It would be nice for her to form an attachment to a toy rather than one of our arms, but nothing seems to be working at the moment.
Does she have anything soft that she likes to play with, either during the day or in the car? That might be something to try. Or, you can buy something new, like a small muslin or taggie blanket or a stuffed animal. It's not really something you can force though, so while you can put them in the cot and hope she takes a liking to one, don't worry if she doesn't. I'm assuming she still has the dummy, so that can be a comfort item at this point.
Before sleep training, it's important to look at her daily routine, i.e. when she wakes, when she naps, when she goes to bed as that can really make a difference in your success. Can you post what that looks like so we can take a look? Also, it will be important to put her into the cot awake for all sleeps, as that will help her to resettle when she wakes as she will already know where she is. Is she currently teething? If you're planning on going through with this while she is (which is just fine), I would make sure you've given her meds before putting her down as well.
Hope that helps a bit... we are happy to hold your hand as you work through this!