I have some theories about Stevens age
rupphire-trash
1) What if Steven is older than he looks. IanJQ had stated before that we don’t know Stevens age because it’s a spoiler. So perhaps because he is half gem, he ages much slower than an average human seeing as how he can manipulate his appearance and gems are technically immortal. 2) What if he is around 12 years old but the reason it’s a spoiler is because we either get to see an episode of rose turning into Steven or around the date of his birth, something really important happens. Something that would explain the reason for his birth.
spockvarietyhour
3) Steven was born 3 minutes before the cookie cat episode.