javax.validation.valid on child objects

I've got a simple structure

public class Parent {
    @Size(min = 5, max = 10)
    String lastName;
    List<Child> childs;
}

public class Child {
    @Size(min = 5, max = 10)
    String firstName;
    @Size(min = 1, max = 18)
    Integer age;
}

and a method with definition

@ResponseBody
@RequestMapping(method = RequestMethod.POST, consumes = "application/json", produces="application/json")
public RestResponse create(@RequestBody Parent object)

which creates (and gives a possibility to update) parent objects.

Let's assume that I'd like to create two functionalities:

1) To create a working copy - user doesn't have to insert correctly all of the data.

2) To send me this data - in this example I'd like to valid if they're correct.

I've found that there is a way to valid it by adding @Valid annotation to the parameter in method definition, like that:

@ResponseBody
@RequestMapping(method = RequestMethod.POST, consumes = "application/json", produces="application/json")
public RestResponse create(@RequestBody @Valid Parent object)

but it do valid only parent field, skipping childs. I can add @Valid annotation on child list:

public class Parent {
    @Size(min = 5, max = 10)
    String lastName;
    List<Child> childs;
}

but it'll work all the time - even when I'd like to save a working copy. Is it possible to valid objects inside parent object conditionally?