There is a lot of information available online on training dogs. You might not be interested in a long obedience training routing, but I bet you can find the basics to reinforce good behavior. Good luck with her. She needs you for sure and your elderly pet also deserves not to be displaced. Here's a link to a short article about just what you're talking about
:
"How to make your new dog's adoption work for life".
http://www.dogsindanger.com/HowToMakeAdoptionWork.pdf