Thank you for the swift replies. Maybe I should have elaborated a bit more. She's not a rescue; we re-homed her from a family that had her from 8 weeks and now I look back on their behaviour towards her, she was definitely the dominating force in the house. She is great with other dogs and we try to socialise her as much as possible. We both work and we are both away for about 6-8 hours three days a week so she is on her own, I know this isn't ideal but she is walked morning and evening and gets at least an hours worth of walks on those days as well as play time after work. The other four days of the week at least one of us is home all day with her and we take her to a dog park for a couple of hours, as well as a 40min+ walk in the evening and some play time.
HBP, It's certainly a relief to hear that other pups have appeared rather aggressive with their biting too! You're right about the behaviourist, we have already contacted one and are in the process of arranging a 1-2-1 meeting with her and Millie (Our puppy! Just realised I hadn't said that), we were curious as to whether we should both be there? Or is it ok with just one of us?
We're both new to Cockers but have each had 18 years+ experience with other dog breeds, I guess it's a matter of finding a method that works best for her and sticking to it. As I mentioned before,
Pearly, tapping her on the nose was a desperate last resort and hasn't happened since!
And Murphy, Millie has started to shuffle under our tv cabinet, unplugging my xbox from the power block in the process so I feel your pain

I wasn't sure whether to take Millie out for walks when she goes hyper, wouldn't that be rewarding her behaviour?
Thanks again for the support, guys, and apologies for originally posting this in the wrong section
