Can Spanning restore child records when restoring parent records?

Yes, Spanning offers restores of child and grandchild records, all the way down the hierarchy in a bulk restore process. Spanning can automatically restore all the associated child records all the way down the hierarchy, and maintain the relationships during the restore process. Restoring child records automatically when restoring parent records can significantly reduce the amount of time and manual effort it takes to get the data back in the same-org or cross-org. 
 
Note: Spanning restores child records that are related by the “Master-Detail” relationship in Salesforce, where deleting the master (parent) record in Salesforce cascade deletes all associated detail (child) records. 
 
Same-Org Restore: When restoring records back to same-org, Spanning can restore child records for deleted parent records only and not for updated parent records. 
 
To restore child records in a same-org restore by searching for parent records, follow the steps mentioned here:
What is Spanning Backup for Salesforce Bulk Restore?
 
To restore child records in a same-org restore by uploading a CSV file, follow the steps mentioned here: Can I restore Salesforce data by importing a CSV file?
 
Cross-Org Restore: When restoring records into a different org, Spanning can restore child records for updated and deleted records.  
 
To restore child records in a cross-org restore by uploading a CSV file, follow the steps mentioned here: 
How do I perform a cross-org restore?