My mom was very very similar, and she is pretty hormonal already and a widow.
After several years of her breakdowns, I had to have a big sit down talk with her. It was hard, and she hated me for a while, but our relationship, as well as her relationship with others has improved greatly as she discovered how to calm herself a little and she realized how much we really do love her.
I basically just started off by telling her how much I love her, and that I have some concerns. I told her she probably is well meaning, but her extreme behavior pushes people away, instead of draw them to her like she wants. I told her that if she could simply respect us and not get her feelings hurt all the time and try to lay guilt trips on us over everything, that it makes us not want her around.
I point blank asked her, "would you rather us invite you out because we love you and want to spend time with you, or because you guilt us and we will dread your behavior and not have fun?"
She understood and we have worked really hard and are great friends again. Just be sure to enforce how much you love her, and want her to be happy, but she needs to make some effort as well.
Also, remember to pick your battles. ''Professional victims" can't distinguish between a stupid little off remark or a huge issue, so save your energy for those issues and ignore the annoying little stuff.
As for the dog, I would maybe ask a friend to house sit for her stay. Not worth the trouble, but don't hide the dog. Let her know you have one, but it will be taken care of, and sincerely mean it, otherwise she will take it as if she made you do some huge burden and that will not go over well. She may greatly appreciate your sensitivity to her anxiety.