Isaac's merit was her absolute loyalty to Kiara, and though she didn't understand everything, if Mrs. Kiara asked her to do something, she would do it without hesitation and took Kiara to the Hospital.
Kiara didn't go to the previous Hospital, because that place was filled with her parents-in-law's informants. If she were to be admitted there, her parents-in-law would find out immediately and come over, and then the act could not continue.
The Hospital connections had all been sorted out by elder Brother. When Kiara arrived, she complained of headaches, memory loss, and general malaise, along with insomnia, forgetfulness, and frequent fainting spells. The brain being the most intricate organ of the body, once she mentioned these symptoms, Doctor immediately ordered a variety of tests, all expensive ones, to be done. The conclusion was that they couldn't confirm if the damage was caused by that past episode of oxygen deprivation to the brain.