Why not have them land in Canada as soon as possible? Afterwards they can choose continue their healthcare in home country or enrolled for Canadian healthcare.
From the looks, both siblings does not have significant family ties outside of Canada. As they are from India, CAD 11k is probably not enough. Your funds are not considered.
I have no similar experience but not unheard of. Some people were denied entry even visa was granted and later cancelled. This probably a better situation than arriving at the border only to find that one's visa was cancelled (or simply denied entry) and had to get a flight to leave the...
I think the person will need to provide document such as PR card, PRTD, ETA, visa and etc. before boarded. Also, Canuck only mentioned "air". I suppose someone also cross international borders through marine vessels.
Assume she has US visa, in August 2026, you pick up her in a US airport and return together to Canada. Once she's in Canadian soil, she apply for her PR renewal.