Actually, it is very common for dogs to make noises while sleeping. Many dogs, my own included, will whine and bark while asleep and mine will even twitch and tremor sometimes. While we don't know if they are dreaming, it seems like the brain waves and such when measured are similar to humans in deep REM sleep. Assuming that she is acting normally today, I don't think i would be too concerned about it.
I hope that helps! Please let me know if you have any further questions!