No offense but some need to learn English before they offer to help others with it.
Am not going to be technical but the spelling mistakes here don’t qualify you to help with the language.
as for the subject it self, there is no harm to correct some mistakes others done, of course DO NOT do the whole thing for them, but if they made an attempt, then no harm in correcting and helping your brothers and sisters.
Selfishness will lead you no where, one day you will look for help yourself, let me know how you would feel when you know others can help you but DONT