First, welcome and congrats on your daughter's wedding
I would start by going to the CIC website
Welcome Page | Page d'accueil and requesting a complete application kit. There are specific applications by regions.
Then I would read it, re-read and read again. The information required is not difficult the forms can just be a bit confusing.
After reading it over a few times she will have a better understanding of all the documents needed from both herself and her husband.
Where does she live? In Quebec there are some extra requirements. If not in Quebec, you do not need a minimum salary to sponsor a spouse.
She can apply while living in the DR - there is a section about sponsoring while living abroad in the application.
Once she has the application and read it over - then she may want to join this board. There are many of us that have been through the process sucessfully - she will find a lot of knowledge and a lot of support here.
Best of luck to her