As your sister is in the first year of a Masters degree, she has started this study program pretty recently and she is not even mid-way through it. This means her study ties - which are her only ties - are NOT strong.
IMO, she must not apply for a TRV until she is in the second year of her Masters degree. It's your call though.
If she decides to apply then:
Actually am not the host. Its my cousin. We are submitting the marriage card and invitation letter from host and my father's bank balance, property evaluation, and income details .
It would be better if you invite your sister, not your cousin. Don't think about *host* as what one considers typically for social events.
You must provide an invitation letter + copies of your passport + PR card + your NOA/T4 + your bank statement (reasonable balance), etc.
Purpose of visit:
Keep her visit to 2 weeks max.
Don't limit purpose of visit to just the cousin's wedding. Prepare a day-by-day detailed plan with expense estimates like a typical tourist + your cousin's wedding (his/her wedding invitation + other proofs of the wedding and reception).
For your sister's finances:
A Letter of Financial Support from your dad + his 6 months' bank statement + any other financial investments (liquid funds) + his ITRs + if she has any add-on credit card (primary card owned by your dad) + 2-3 months' credit card statements
Your dad's property is irrelevant as your sister does not own it.
For your sister's study proofs:
Letter from the college stating she is a bona fide student and approved leave from XX to XX dates + tuition fee receipt + college brochure/website + any mark sheet or transcripts + student ID + any exams/project work that's scheduled after her return
If she is a member of any volunteer or charity organization or sport club.... and must return for a specific event after her Canada visit (evidence of this)
