correct her mistake. i think this part is important as well. know better, do better.
overall this is a really cute story and a dog one, despite dogs not being my favorite pets (cats and birds win, sorry not sorry) i actually really connect with! stick to your decision to break up. you will only end up confused and confuse your partner if you start to change your mind. your relationship will never be the same if you change your mind.
always end your relationship before starting a new one with someone else. 