The general consensus is to wait at least three months between taking Reiki I and Reiki II, and at least a year between taking Reiki II and Reiki III. This is because every attunement opens you up to new experiences (which can differ for each individual), and it takes time to get used to this and to practise your new reiki skills. It is also important to try and incorporate the reiki principles into your daily life, which can also take time.
I'm sure Rita will be offering Reiki Master classes again in the future. I can let her know you're interested if you'd like. Just let me know.
Hope you're doing well. Miss you! Give Roy a big hug for us!