I agree with Ginger, it does sound like some type of seizure. The only thing is seizure activity USUALLY lasts only maybe 30 seconds to three or four minutes. Ten minutes seems like a long time.
Your dog is in the right age bracket for genetically carried epilepsy to begin. Seizure activity is usually first seen between the second and third year, although it can occur at any point in the dog's life, most of the time seemingly out of nowhere.
I would do as Ginger suggested - I would address my question to the Ask A Vet forum, and then I would make a vet appointment for her first thing Monday morning. If there are any episodes in the meantime, I would take her to an emergency vet that is open when regular vet hospitals are closed.
IF it is epilepsy, if it is a simple case of idiopathic epilepsy (not caused by an injury or disease), it is usually fairly easily managed with medication and the dog is able to live a mostly normal life. Unfortunately, epilepsy is all too common today in many breeds, because too many people who are breeding dogs are not aware that they should not be breeding dogs that have diseases that are transmitted genetically.
Unless you know the full history behind your dog's parents, the best thing to do is start at square one with a full physical by your veterinarian, including a full blood panel and possibly even MRI of the brain to see if there are any masses or lesions present, and when the results are known, then you can figure out which direction you're going to go in. Good luck, and please keep us posted.
Ghilly
This could have been a form of seizure.
A good idea would be to post your question in the "Ask a Vet" forum. There is a link through to that if you scroll down this page, on the right. You will get a reply from a vet there, although if the questions have already reached their daily limit, you may have to wait a little while to be able to post.
However, why wait? Why not take your dog to the vet when they open Monday, and get her fully checked out. If this strange thing happens again to her in the meantime, take her to the emergency vet.
It is very possible if she is prone to these seizures, they may well be controllable with medication. Get it checked out.