I would say to all parents who think their child is gifted, or advanced, at a young age to concentrate on their social side. Watch them carefully. How do they interact with their peers?
My three year old is advanced. She's just three. She can write, legibly, her name and 'mummy', 'daddy' and her sisters name. She knows her phonics, and can blend 3/4 letter words. She counts, adds simple sums, completes 50 piece jigsaws. Draws people and animals with all features in the right places. Etc etc etc.
I also suspect that she is autistic. She tip toe walks, mixes happily with other children on the surface but is extremely sensitive to noise, doesn't understand others social cues well, has a limited diet, sorts toys, loads of other markers. She won't meet the criteria for an NHS assessment because she, on the surface, mixes well without apparent distress so I will seek a private assessment.
Experience tells me (because my eldest was the same, is working happily on year 3 work in year one but diagnosed autistic and I am also on the pathway) that this is how my children are. Bright, engaged, avid readers, advanced academically.... but they struggle socially and even if a child is neurotypical, at a young age the focus must be on their social side/skills or they will struggle later on.
Encourage them by all means if they enjoy learning. But also encourage play, play play. Take them to soft play, to the park, engage them with peers. If they're advanced, they'll do well at school without struggle but they won't if they can't cope with the environment/people.