Scylla is correct. The person in the article was not sponsoring her child, and therefore was not excessive demand exempt. She was applying as a live-in caregiver. Spouses and children, when being sponsored, are exempt from that clause.
The notes you highlighted indicate that there was nothing that would be a danger to public health, and nothing about excessive demand, since your wife is exempt from that.
This is what CIC has to say about medical inadmissibility:
CIC has the policy responsibility with respect to inadmissibility on health grounds [A38].
A38(1)
38. (1) A foreign national is inadmissible on health grounds if their health condition
(a) is likely to be a danger to public health;
(b) is likely to be a danger to public safety; or
(c) might reasonably be expected to cause excessive demand on health or social
services.
Exception
None for A38(1)(a) and (b).
A38(1)(c) does not apply to a foreign national who:
has been determined to be a member of the family class and to be the spouse,
common- law partner or child of a sponsor within the meaning of the regulations;
has applied for a permanent resident visa as a Convention refugee or a person in
similar circumstances.
is a “protected person” (within the meaning of subsection A95(2)); or,
is, where prescribed by the regulations, the spouse, common-law partner, child or other
family member of a foreign national referred to in any of the aforementioned (A38(2)).
