
That's an awfull lot of weight to put on in such a very short time!
My only suggestion for you would be that you will have to cut down on whatever you are feeding her. Is she having any treats or is someone else giving her treats!
My 5 cockers healthy weights vary from between 10.5 kg to 12.5, I never allow them to get heavy, it is as simple as cutting down on the amount being given, hungry or not!
Take no notice of the guideline amounts, they always recommend too much. You must use your own common sense on the amount you give her and give her a lot less.
What might help with the hunger is to give her a variety of raw vegetables chopped up small or liquidised and add to her meal.
Whole carrots, broccoli stalks, sprout stalks fruit and all sorts of the vegetable range can be used as treats. Ours love it all.