She.D said:
Either your or both yours and your husband's join income should meet the MNI for PGP for 2012, 2013 and 2014. In your case, you're family of 4 (you+your husband+your mom+your dad). If you read the guide (which you should have done before), you will find the income level for 4 people:
2012: $54,685
2013: $56,280
2014: $57,125
If your family income is over this limit, you're good to go. Mind you, your husband will need to co-sign as a sponsor if you're using his income along with yours.
2. which of the following form I should fill for them;
Again, these are well written in the guide.
Document Checklist — Sponsor [IMM 5771 ] May 2015
Application to Sponsor, Sponsorship Agreement and Undertaking [IMM 1344] (PDF, 539.27 KB) August 2014 - Required
Financial Evaluation for Parents and Grandparents Sponsorship [IMM 5768] November 2015 - Required
Schedule A – Background/Declaration [IMM 5669] (PDF, 777.30 KB) December 2012 - Required
Statutory Declaration of Common-Law Union [IMM 5409] (PDF, 636.51 KB) April 2015 - Not Required if your parents are legally married
Generic Application Form for Canada [IMM 0008] (PDF, 496.57 KB) November 2015 - Required
Additional Dependants/Declaration [IMM 0008DEP] (PDF, 424.19 KB) August 2014 - Not Required for you
Additional Family Information [IMM 5406] (PDF, 570.00 KB) September 2013 - Required
Use of a Representative [IMM 5476] (PDF, 648.31 KB) June 2015 - Optional
Fee Payment Form [IMM 5770] August 2014 - Required
Instruction Guide [IMM 5772] - This is just a guide for you to fill out the application
3. Can I apply for my sister as well
No, you can't. She is way over the age limit.
Note: Some forms need your parents' original signature. So, if they are not here with you, they will need to mail the signed form back to you. Since the holidays are progressing fast, you have to be quick in gathering docs if you haven't done so yet. The 5,000 cap may/will be filled out on the very first day (Jan 4, 2016). Therefore, you have to make sure that you application package reaches CPC-M on Jan 4, 2016 (preferably by noon).