I think I would go right back to basics - practise walking to heel (- well she is a cocker, so the nearest you can get to it - lets just say a „disciplined walk!
) Everytime you stop, get her to sit and reward, you can then lengthen the time she‘s sitting before you carry on. When you do decide to carry on walking, give her the command to do so (heel, come along, lets go - whatever you use). The aim is, that she should sit whenever you stop, once she‘s doing that automatically, build in meeting someone, stop, have a very short chat and then carry on (keep it very short at first and then gradually extend). Remember to praise and reward when she does it right. I would also practise a stay command in the down position, again in a quiet place and then build up the distraction. - Sit, Down, walk a few paces away and come back, - reward if she‘s still lying down. You can build that up so that you‘re further away and she‘s stays where she is for longer, - try not to look at her or give her attention, - if she gets up and comes to you, just take her back to where she was without comment and start again. Again, praise and reward for lying quietly. All forms of scolding her and telling her to be quiet are actually just giving her the attention she wants and she won‘t listen or learn in the stressful situation, you need to practise the behaviour you want in a relaxed environment, where it doesn‘t matter if it doesn‘t go right - you CAN ignore her properly when you‘re not in a place where you‘re feeling embarressed. I think we‘ve ALL been there, but its impossible to start and try and train something when face you‘re alread in a difficult situation (a bit like having your first driving lesson on the M6 in rush hour!!) The ultimate goal is that she learns self control and sits or lies down quietly for an extended length of time.
These little monsters pick up SOOOO quickly on how we‘re feeling and, mine at least, is so excitable I have to get him and me really calm before I can even think about teaching him anything. My first trainer told me not to try and train unless I was in the right mood myself, staying calm and masterful (for want of a better word) is key. If time is hort or you‘re stressed, leave it dor another day.
Hope this all makes sense - what I‘m trying to get across is that it sounds like Mia is starting to try and get her own way (like most teenagers!) and she needs to learn, in a kind way, that you decide when you‘ll play, walk, talk to her etc and when your attention isn’t on her, that she knows she should be calm and quiet - has nothing to do with dominance, but you are the one in charge!!