Usually NSAIDs are given after spays because they are thought to work best.
If Bella doesn't have any underlying medical issues (especially liver), everything should be fine. NSAIDs are never my first choice but the risk is minimal. Carprofen (Rimadyl) is a very popular drug post spay.
If you are concerned or you think she is having side effects from it, you can always have blood work done.
I think for the short amount of time she is going to be on it though, as long as she is healthy, everything should be fine.