Just to add to Tom's post.
He says: select the best looking cell and remove the others
If selecting a single cell choose an open one - you know it has a larva in it, it will be less likely to be a 3 day old larva chosen as an emergency cell, and finally you are less likely to spoil the cell c/f a recently capped one, that is very fragile.
If selecting a capped cell, select two is the usual advice (small risk of a cast swarm, but only one, if it happens) - but in your case you still have a back-up colony for a further try, if initially unsuccessful.
Personally I would check quietly for an empty cell (particularly if only one capped cell is left) about three days after expected emergence and then leave 3 weeks at least. That would be before she would be mating and save a further 3 weeks if a dud cell. Any further checks (if really necesary) should only be carried out when she would not be on a mating flight and beware - she can fly - if you do open up!
So, you can see there is just a little more to consider, than simply picking a good looking cell and waiting 4 weeks.
Regards, RAB