Rowan 'went wild' and 'screamed'

I have a very laid back, peaceful 14 year old calico cat named Rowan, who normally is the worlds most laid back cat...nothing ruffles her fur. She seemed a little 'different acting' last night... restless... She has been eating well (including several hours ago) ... no problems with the litter box ... I know that cats all of a sudden 'go wild' and race about ...But Rowan was just sitting there and suddenly just screamed a ear piercing yowl!...and then started jumping up on everything she could...bouncing around. I managed to calm her down and gave her some Bach's Rescue Remedy and she is now quiet...but in the 7 years she has been my companion...she has NEVER displayed this behavior. I guess I would appreciate comments and encouragement. Thank you, everybody. I'm new to the site.
Love, Hathortemple

First let me say hello and welcome ! I would be concerned or aware of this sudden behavior change as well, so you aren't alone...
One thing I can say is that a lot of cats do what you a describing before hairballs or throwing up, older cats often howl because of the uncomfortable feeling. I would keep a close eye on her, especially if she didn't throw up, it could be some other discomfort. Or a simple behavior change, your instincts will tell you the difference ........