So she's been thee twice since 2011 and you and she never addressed her property or dog issues? If I were her I would argue that you agreed to store the goods as evidenced by her twice returning and you not mentioning anything about the rent money and your never sending her a notice of intent to dispose of her items. Had you acted in writing, in those first days and weeks after she left, you likely would have had perfectly legal grounds to sell, dispose, or donate the goods.
You MAY have an oral agreement, but they are difficult to prove to a courts satisfaction without conduct evidence which you may or may not have. It think you are in a weak position and you should see a local attorney who MAY, on discussing the facts more closely than can be done on line and MAY find you some stronger ground on which to withhold her property and dog.
READ THIS BEFORE CALLING OR EMAILING ME: I am licensed to practice before the state and federal courts in Virginia. We have not established an attorney-client relationship unless we have a signed representation agreement and you have paid me. I give a 100% effort to get you on the right track with your issue. Sometimes that means legal educational information, sometimes that means counseling and non-legal guidance. You should speak with an attorney to whom you have provided all the facts, before you take steps that may impact your legal rights. I am not obligated to answer subsequent emails or phone calls unless you have hired me. I wish you the best of luck with your situation.
I agree with my colleague about the personal property.
Do you want to keep the dog? If you do, tell her she is going to have to reimburse you for all your expenses in caring for the dog (food, vet, etc) as well as a daily boarding fee for the time the dog has been with you ($25 - 35 per day), or, she can agree to let you keep the dog in lieu of payment. Make sure you get any agreement IN WRITING.
If you don't want to keep the dog, you should still tell her that she is going to have to reimburse you for all your expenses in caring for the dog (food, vet, etc) as well as a daily boarding fee for the time the dog has been with you ($25 - 35 per day).
If we do not have a signed fee agreement I am not your attorney and this is not legal advice.