It is feminine like holka. Actually děvče is kind of an exception. When it comes to people, grammar genders tend to match the reality.
And these days the word děvče is not even used that often, because it sounds really formal. I personally prefer using words holka or holčička (little girl, usually for babies).
Isn't dívka a bit older than holka? Like dívka is a young girl and holka is a little girl?
nope. it is more of a regional difference than age of the girl. If the girl was really little, like 0-6 or so, she would likely be called HOLČIČKA or DÍVENKA or DĚVČÁTKO which are diminutives of holka, dívka and děvče and again, word used is more likely based on region.
“Are you girl?” Would be an acceptable answer since in czech doesn’t specify the number…