Hi
Have you spoken to her breeder about the heat cycles of the maternal line, especially her dam?
I have one line, and they come into heat late for the first time, very late 18-24 months, but once they have the first heat, they then tend of go about every 7 months.
I also had one girl (she is spayed now) that you could set a clock to, I could almost predict the day that she would come into heat, she was that regular.
Personally I wouldn't get worried until over 2 yrs had past, and silent heats are a huge pain in the arse, especially if you don't have a male around to tell you what is going on.
Good luck and take care
Lynn
