Yes, you can use an S-tag as normal and push that content to the child events. If you hard code the blueprint's FR_ID in the S-tags, when you push the content out to the child events the blueprint’s FR_ID will be replaced with the child event’s FR_ID automatically.

Note that if you are using the WYSIWYG instead of implementing S-tags by hand, the S-tags inserted by the WYSIWYG will have the blueprint's FR_ID and thus will work as desired when the content is pushed out to child events.