Robin,
That's not surprising. Let's look at a calendar. It's been 24 days since June 14. Let's say the colony started with an egg laid on 6/14. It could be sooner, but this is the only date we have. 16 days from egg to emerged queen. That's 6/30. 1-2 weeks to mate 10-20 times. Another possible week to figure out how to lay eggs. So up to 3 weeks after 7/1, which is 7/20.
So it may be another 2 weeks before she starts laying.
The colony may be aggressive, this is normal. Three big things keep them calm and happy. 1) Queen with correct pheromones. 2) Pheromones from brood (larvae). 3) Food. Yes, there are other things like overcrowding, attacks, weather, etc. But these are things inside the hive. Make sure they haven't backfilled all their brood area with honey/nectar. If she doesn't have room to put eggs, she won't!
As I say, close the hive and step away! You've done a good job: you identified that they've made a new queen and she's emerged. Great. Now let them do their thing. If they're short on food, you can give them 1:1 sugarwater. If they're overcrowded, add a super (but they won't be if they've been queenless for 3 weeks). Otherwise, sit back and celebrate your good bee husbandry work.
You hadn't mentioned that they swarmed. Did you see them, did you get your own swarm?