Your chameleon sounds like she is doing fine so far!
You don't want to let her see you watching her when she is digging the hole(s). If she sees that she is being watched, she will likely abandon the hole and start another one when she is not being watched. If this happens often enough, she could become eggbound. A veiled may dig for several days and may even dig in several different places until she finally turns around in the hole and lays her eggs.
Its important IMHO to always have a container of sand/soil in an egglaying chameleon's cage so that she has a place to start digging when she is ready to lay her eggs. Two of the most common causes of eggbinding, IMHO are lack of an egglaying site and being watched during the digging process.
Its okay to let her see you if she is back up in the branches. Its okay to feed and water her when she is up in the branches.
During the time that she is digging holes, its not advisable to leave insects loose in the cage because when she is in the process of laying the eggs the insects could chew on her or when she has laid the eggs they could chew on the eggs....but if she is willing to eat, then feed her.
You asked about if the tunnel had shifted or collapsed...she should still go back and dig again.
Once a female chameleon has laid her eggs, I always let her finish burying them completely and return to the branches before I dig them up.
If they are fertile, do you have a container put them in and an incubator ready? If you have any questions just ask.
Good luck with it all!