When they're still young, I remove them, and by the time they're old enough (time will tell if this pans out with her brother) they come, knowing that there is no other option.
Pick your hills
I don't like the phrase "Choose your battles," but I get it. Like choosing the proverbial "hill to die on," and so on.
I don't care what my kids wear. I don't care if they have a jacket on in the cold. I don't care if they get dirty. I don't care if they don't want to learn to climb the jungle gym. I don't care if they want to ride their bike or walk. I don't care if they want to fill their backpack with blocks and carry it around for the day. I don't care if they want their sandwich cut in strips or squares.
I do care about a few choice things; they are not permitted to do anything harmful to themselves or others, or anything that is simply unkind.
Yes to both of these. In the toddler/preschool years, just making things happen laid the ground work for obedience as they got older and bigger.
There are very few things that I really care about. My kids have always had tons and tons of freedom. They've gone out to eat in dress up clothes (as in princess dress, wellington boots, umbrella with frogs on it, and baseball cap, because you can never have too many accessories). They have free range of the food in our house (which is all stuff that I'm fine with them eating.
The things that are a big deal to me are nonnegotiable, and they know it. Keeping the list very short helps a lot. For me, part of successful GD was keeping the list short. For a while, it seemed that our only rules were:
1. Teeth must be properly brushed at bedtime.
2. Always wear a seat belt.
3, Don't make your sister cry. Although this negatively stated, it worked for them.