Goldorak provides good advice.
Easyjet is quite reliable, but a 3h connection is tight.
This is a flight late in the day, so more prone to possible delay. It really depends on the day (holidays) and ATC problems due to weather, industrial action or heavy traffic.
For example U2 8045 arrived after 21:30 on 7 July.
From arrival, I would budget 1h to reach QR check-in counter with bags and kids: walk to immigration, clear and collect bags, walk to train, walk from train and find QR check-in counter. That leaves you a leeway of one hour.
If you miss your QR flight, you will not be protected in case you miss the connection.