diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index abe8d56cb8f..57af3d5af77 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -7,10 +7,6 @@
 
     *Rafael Mendonça França*
 
-*   Remove deprecated `ActiveSupport::Notifications::Event#children` and  `ActiveSupport::Notifications::Event#parent_of?`.
-
-    *Rafael Mendonça França*
-
 *   Remove implicit conversion of objects into `String` by `ActiveSupport::SafeBuffer`.
 
     *Rafael Mendonça França*
diff --git a/activesupport/lib/active_support/notifications/instrumenter.rb b/activesupport/lib/active_support/notifications/instrumenter.rb
index eefca19b191..a6f83e88d11 100644
--- a/activesupport/lib/active_support/notifications/instrumenter.rb
+++ b/activesupport/lib/active_support/notifications/instrumenter.rb
@@ -165,6 +165,23 @@ module ActiveSupport
         @allocation_count_finish - @allocation_count_start
       end
 
+      def children # :nodoc:
+        ActiveSupport.deprecator.warn <<~EOM
+          ActiveSupport::Notifications::Event#children is deprecated and will
+          be removed in Rails 7.2.
+        EOM
+        []
+      end
+
+      def parent_of?(event) # :nodoc:
+        ActiveSupport.deprecator.warn <<~EOM
+          ActiveSupport::Notifications::Event#parent_of? is deprecated and will
+          be removed in Rails 7.2.
+        EOM
+        start = (time - event.time) * 1000
+        start <= 0 && (start + duration >= event.duration)
+      end
+
       # Returns the difference in milliseconds between when the execution of the
       # event started and when it ended.
       #
diff --git a/guides/source/7_1_release_notes.md b/guides/source/7_1_release_notes.md
index 5994c70594b..9f53a5c55e9 100644
--- a/guides/source/7_1_release_notes.md
+++ b/guides/source/7_1_release_notes.md
@@ -166,8 +166,6 @@ Please refer to the [Changelog][active-support] for detailed changes.
 
 *   Remove implicit conversion of objects into `String` by `ActiveSupport::SafeBuffer`.
 
-*   Remove deprecated `ActiveSupport::Notifications::Event#children` and  `ActiveSupport::Notifications::Event#parent_of?`.
-
 *   Remove deprecated support to generate incorrect RFC 4122 UUIDs when providing a namespace ID that is not one of the
     constants defined on `Digest::UUID`.