Sounds like a smart woman.
Can't help but wonder how long you're going to last with her
The problem with "let it happen when it happens" is that generally, people can be lazy. This woman, by setting a time frame, no matter what the events are in her personal life, is holding to her requirements (for letting her children meet those who she is dating), which considering is related to her children, shows remarkable parenting skills, particularly IMO if it's a good amount of time (to meet the children)
I've personally found working through a volunteer organization, that you set rules and procedures in place to prevent future mishaps that you LEARN by from experience. Perhaps a rule make not make much sense to you, but in reality, those procedures are in place to save people from disappointment and wasted time.