How to delete from two tables same field name in single query?
A DELETE only affects one table at a time and removes all rows that are defined in the criteria.  Notice the syntax description:

DELETE [table.*] FROM table WHERE criteria


You should be able to wrap two DELETE statements in a transaction. Because PersonalTrainerMasterData contains the criteria, DELETE it last. E.g. 

BEGIN TRANSACTION
   DELETE * FROM PersonalTrainerCheckboxData WHERE ...
   DELETE * FROM PersonalTrainerMasterData WHERE ...
COMMIT


If needed you could also insert logic to decide whether the DELETE should be allowed to COMMIT or if it should ROLLBACK.