Catie, I'm just gong through this with a client of mine.
My solution was to have a summary of the maximum of the recurrence start date of the child records and I decided I always wanted to have 2 future children always be in existence.
I set up a formula on the parent to calculate the next recurrence date.
Then I created a flag field to indicate if the parent record was eligible to have another child created.
Then I set up a saved table to table import to create the next Recurrence if the parent was eligible,
Lastly I set up an Automation to run daily that import say 10 times in a row (In my case the start date could have been in the past). In most cases, after the import ran few times there would be no more parents left who needed a child created.