The outcome is more important than the actual process. Hopefully, they will do it better. Timing is also very important. Be sure you choose the right time to do the training and the delegation. It will do no good to overload another person.
Some people are capable of handling more than others.
In other words, don't set them up for failure. The art of delegation is really a sharing of responsibility and authority with another. There must be a benefit to be gained by both of you for this sharing to be successful. The last step is to develop a simple way to track and receive feedback on performance. Write down the specific results you are looking for and develop a simple system, maybe a chart, to monitor those results.