I also wouldn't be worrying about toielt training, bottles or cots right now.
Try not to think of it as a power struggle, your relationship with your child shouldn't be a win-lose situation, you know? You're working together to find compromises that work for both of you.
So, if for example you need a break and she needs to let off steam, then playgroup or a trip to the park might help. And definitely pick your battles, if she's arcing up over something that's really inconsequential to you, then maybe just let it go.