If you are desperate of not breeding her than spaying is the best solution - and as Dawn B wrote, not only because of the heat itself.
The one and only thing against spaying is that it is non reversable. And you may regret at the age of 5 years...or whenever.
Whatever you decide, I would not spay her before the age of cca 9-12 months.
You have time to think until then.
I have spayed and neutered quite some dogs which didn't make the grade, I think life is much easyer with a spayed/neutered dog.
ATB,
Anna