Hi. Yes, we applied online. We are all living in the Phils right now so I did most of the work and just showed it to my wife. If you are in Canada and your parents in Phils, you yourself can do the application online but just make sure the MyCIC account is in your Mom's name. They can take care of their document scanning and email the scans to you for uploading.
Applying online is much more efficient and cheaper than printing and sending everything. You should be able to invite your step-dad as well. Just make sure you include everything they ask for plus proof that they will leave at the end of their stay (Land titles, Employment Letters, Family Ties, etc.) It is time-consuming and not easy to get documents gathered but once everything is there, it is easy to upload using the MyCIC system, and I'm incredibly impressed by their speed considering a backlog of applications resulting from the strike.