there is.. an unmuzzled one!!

but yes...please keep her onlead til things r sorted and please spay her

Re spaying - an aggressive bitch can get worse when spayed. This is due to the increase in the percentage of testosterone. So while a timid bitch may well improve, a bitch who has learned to control her space through agression may well become worse.
(For the same reason, a timid dog may become more so when neutered - it is the testosterone level that fosters belligerency)
The fact that this bitch chooses her targets leads me to suspect that fear may not be the cause.
It is always better IME to address the issues before neutering. For one thing, the effects of changing hormones don`t complicate the behavioural issues.

However we have already established that this bitch only developed this behaviour after her last season and her phantom pregnancy at 4 years old, therefore this bitch is NOT "aggressive" it is demonstrating hormone related behaviour........

The very fact that her behaviour is RANDOM indicates this as well. IMHO

Suggest you take her to the vets & get ger thyroid levels checked. She is at the age where thyroid related issues can occur & behavour changes are one of the symptoms

Ask your vet to check her TSH, T3 & T4 levels.

You have had good advice, but just wanted to add, I had a unspayed JRT (years back) who at the age of 9 had a phantom pregnancy, she changed drastically afterwards, attcking other dogs and becoming quite aggressive. It was suggested by the vets I worked at to have her spayed and within 4 months she settled back into being the dog she was before.

Just thought I would give you my experiences