Original: Uccello was married to Tomassa Malifici by 1453, because in that year Donato (named after Donatello) was born, and in 1456 his wife gave birth to Antonia.
Simplified: By 1453, Uccello was married to Tomassa Malifici. In that year she gave birth to Donato who was named after the sculptor Donatello.