Odd name spellings

My son is just over a year old. His older sister, one of my step kids who is 9 loves making the baby arts and crafts projects. It’s super cute. She spells his name wrong on everything though. Me and her dad have both pointed it out and showed her how to spell it correctly. She gave me another project yesterday and his name is spelled wrong again. A year of showing her how to spell it, and still wrong lol. So what is the next step here, or do I just continue hanging up misspelled things around my sons room.