While this may seem like a cut and dry question and answer, it can get rather complicated. Having said that, let me verify the information as I understand it:
Your dog is an 11 year old, Maltese female. It is unclear from my vantage point whether or not she is spayed, so I will answer as though she has been.
The first thing that I would be interested in resolving is making sure that she does not have a medical problem that is triggering her hunger and need to eliminate at night. These problems can occur because of endocrine problems such as diabetes and Cushings disease.
Once those issues have been ruled out, training issues can be attempted. For this I would start with basic crate training and starting to re-train her to what you expect to be the times and schedule (within reason, of course). This means that she is in a crate when you are gone and at night. The hardest part is likely to be the necessity that you ignore her barking and whining at night for several nights as she gets used to the "new schedule."
I can't stress enough, though, that if she has medical problems driving her need to eliminate and her hunger at night, crate training and ignoring her at night could cause her harm. For this reason, I would encourage you to see your veterinarian and have those medical concerns ruled out!
Please feel free to ask further questions and with more detail if you would like.