any nesting behavior? cleaning a flat rock, assuming you have one in tank, digging? flairs when you first approach the tank, more aggressive than ussuel with the cleaning tube and your hand in the tank?
I'd be interested to hear about her behavior though like pops mentioned. Hopefully its not a disease. Swim bladder issues or bloating could cause something similar. Oh and I used to have a female jag that would lay eggs every 3 weeks for years. She was the the only fish in the tank... must have looked kinda butch in her reflection.
I have had Oscars lay with no male, jags lay with no male JD lay with no male. they all showed nesting behavior. so i am just wondering if another issue,