Best to encourage them is to show them what their peers are doing and they will be more encouraged in wanting to try it out as well. However if she still refuses to, I wouldn’t force her as it will leave her a bad impression towards walkers more. Generally every kid has their own pace, my LO personally don’t use walker but will cruise around with the support of furnitures.
bring her to places or relatives/friends house whereby their kids use walkers, maybe your kid will be influenced to try to use the walker? another alternative is to force her to use it despite her screaming. maybe she will get used to it