Twenty nine and three quarters :) I don't think there's any need to add an adjective to it unless the intention is to convey ~"too young; naive; inexperienced"

Twenty nine and three quarters :) I don't think there's any need to add an adjective to it unless the intention is to convey ~"too young; naive; inexperienced" as seems the case here. They could simply say e.g. "John Doe, 29, [...]".