Today all of a sudden out of the blue, my 14 year old dog started to fall and vomit repeatedly. She also lost control of her bladder. What is this caused from?

Sadly tests would need to be done in order to give you an accurate answer.

It's time to go to the vet, asap.

Good luck.

Good chance it could be neurological or even a chemical imbalance... definitely a vet check.