Displaying the first child page of the parent page

You can use get_pages with a limit of 1:

$pages = get_pages([
    'child_of' => $post->post_parent,
    'number'   => 1,
]);

if ( $pages ) {
    $first_page = current( $pages );
}

Related Posts:

  1. how to properly list child pages in sidebar?
  2. Get custom field value from Grandparent Page for Parent and Child Pages
  3. Given the page id, check if it has children
  4. How to get a list of all recently published child pages?
  5. WordPress get the child pages of current page
  6. Show siblings (if any) and parents
  7. List child pages of current page but limit to specific year
  8. Child page excerpt
  9. Create WordPress child page from page actions
  10. How to show child page without providing ID so it’s dynamic
  11. is_child() function
  12. Drop-Down Menu of Current Child Pages
  13. Get WordPress Child Page IDs
  14. Adding title and description to subpage’s featured image
  15. Show list of Child Post in Parent Post
  16. List subpages in order
  17. parent page grabbing wrong url for child pages – get_page_uri($pageChild)
  18. i want to get the parent id, only on parent -> child -> child page
  19. Get first level children of a page ID
  20. Only one parent page showing
  21. Create a list of pages excluding children of selected page
  22. WordPress Betheme: Unkown subheader image of a child page
  23. How to disable alphabetical sorting page
  24. Structure for calling child pages
  25. Child pages and sub-pages do not appear. Why?
  26. Add link to parent page in list of child pages
  27. Display child pages full template including the content
  28. List child pages, exclude the current page
  29. Listing Child Pages in Random order
  30. How to display child pages with in a limited child content?
  31. Display Tags of Child Pages
  32. Get post_meta of children and compare to current page ID
  33. Display the latest content from subpages of another page
  34. Limit the number of child page displaying
  35. Show the grandmother/father of the childpage
  36. How to Hard Set the Parent Page in Template
  37. Website parent child relationship
  38. Get parent page url to show up when it is in child pages
  39. Check if is on child-page of a particular page
  40. Can I have two child pages of different parents with the same name?
  41. Remove WordPress theme from a specific page
  42. How To Limit Hierarchical Pages Depth (For Custom Post Types) To Children Only
  43. Advanced Custom Fields – Get custom fields from parent page
  44. Child Pages Loop
  45. Get Permalink for the top level parent of child pages
  46. Custom user role that can only edit specific (non-custom-type) page and all child pages [duplicate]
  47. Custom Post Type Permalink For Parent/Child, 404 Page Not Found Error
  48. Show content if parent page has children
  49. Delete Child Posts
  50. Display child pages on a parent and child page using Featured Thumbnails
  51. Can’t change parent page
  52. Javascript that will execute on only child pages of a specific parent
  53. What is the optimal way to filter out subpages from admin?
  54. Share parent path between Custom Post Types and Pages?
  55. Load child template based on parent
  56. Custom Field returning Numerical Value for Image rather than URL
  57. Need wp_query to return all children and grandchildren
  58. How to get all child pages in their parent page?
  59. remove/hide pages from users backend
  60. How do I list the child of a child page [duplicate]
  61. Custom rewrite rule for hierarchical custom post type
  62. List children on child post
  63. child of post type (custom)
  64. Menu with parents, children and or siblings pages display
  65. Append a code when at the current page in wp_list_pages()
  66. wp_insert_post if page doesn’t exist under current page
  67. How to retrieve parent menu item name of current submenu item
  68. Combining ‘depth’ with ‘include’ in wp_list_pages()
  69. Removed custom post type slug but not working for child pages
  70. List Posts For Terms Of A Custom Taxonomy For Any Post Type
  71. get_the_title() gets printed out twice
  72. Display child pages in sidebar of parent page in wordpress
  73. Display child pages in a parent page? [closed]
  74. How to Create a Random List of Child Pages
  75. List all posts with the parent or grandparent of a page with a specified ID
  76. $pages = get_pages(‘child_of=’.$post->ID); Why arguments are concatenated?
  77. Keep page hierarchy in wp_list_pages, even if on a child or grandchild
  78. Sort and display pages with specific custom field (not tag)
  79. How to use wp_list_pages on a grandparent page
  80. If/Else child list for Custom Post Type single template within loop?
  81. Search anything from a Child and Sub-Pages of their Parent page
  82. How do I find out which (page) template file my custom child post is looking for?
  83. How to get an array of pages ID by some page’s slug and all its children pages in get_posts() function?
  84. How to use POST method using custom wordpress button?
  85. How do I list subpages in post editor view?
  86. Getting a value from a custom field from a page that shares a parent with the current page
  87. Displaying Child Page’s Information
  88. WP_Query doesn’t return some child pages even though the database shows them
  89. Load one page with parent and child pages
  90. Childpage title + content on Parent Page
  91. Pages redirecting to homepage
  92. Display title of child pages in shortcode
  93. Elegant way to signify inheritance and relationship between posts
  94. How to check if the current page’s parent is one of 2 different ID’s
  95. Detecting top parent category fails on home page
  96. 404 error on second page load for child-pages
  97. How to make in post Parent page children page list nummbered
  98. Query sub subpages based on specific date?
  99. How to create archive child pages with good Yoast SEO meta?
  100. Displaying child pages and file URL in an ACF relationship field shortcode