fix(curriculum): avoid parent/child terminology in travel agency page hints (#67576)

curriculum/challenges/english/blocks/lab-travel-agency-page/669e2f60e83c011754f711f9.md

@@ -198,7 +198,7 @@ You should have at least three `figure` elements.
 assert.isAtLeast(document.querySelectorAll('figure').length, 3);
 ```
 
-Each `figure` element should contain an anchor element as its first child.
+Each `figure` element should contain an anchor element as its first nested element.
 
 ```js
 const figures = document.querySelectorAll('figure');
@@ -208,7 +208,7 @@ for (let figure of figures) {
 }
 ```
 
-Each `figure` element should contain a `figcaption` element as its second child.
+Each `figure` element should contain a `figcaption` element as its second nested element.
 
 ```js
 const figures = document.querySelectorAll('figure');
@@ -226,7 +226,7 @@ assert.isNotEmpty(figcaptionEls);
 figcaptionEls.forEach((figcaption => assert.isNotEmpty(figcaption.innerText)));
 ```
 
-Each of the `a` elements that are children of your `figure` elements should contain an image.
+Each of the `a` elements nested in your `figure` elements should contain an image.
 
 ```js
 const anchors = document.querySelectorAll('figure > a');