Asking whether a Audi A1 GB Sportback 30 TFSI advanced S tronic is a good family car, is not easy to answer from a technical point of view. The range of families requirements is wide, so this consideration only considers the common aspects.
The Audi A1 brings 5 seats with it which is basically good and sufficient for many families, but the car fluffs when it comes to the trunk - 1090 liters of volume might not be sufficient for most families. There are no Isofix brackets installed. These could be used to secure child seats easily and safely.