Danny has a pet shop, Pet Sweetheart, which sells pets and pet care products. Pet Sweetheart also provides lodging for pets when the owner is away. Linda is a regular customer of Pet Sweetheart as she usually sends her cat, Darling, for grooming and lodging. Recently, Linda sent Darling for lodging in Pet Sweetheart as she had to work in Singapore for a week. While in Danny's care, Darling became ill and vomited a lot. Danny tried to call Linda a few times as he was uncertain whether to take Darling to the vet, but he could not get through. Worried that Darling's health will get worse, Danny took Darling to the vet. He had to pay RM500 for the vet's bill and give medicine to Darling for the next 3 days. When Linda returned, she was upset when she saw that the bill from Pet Sweetheart was more expensive than usual as it included the vet's bill and additional costs for looking after her ill cat. Linda refused to pay as she did not authorize Danny to take Darling to the vet. Danny claims that he had to do so as it was an emergency. Linda wants to know if she is liable to pay.

Advise Linda on the above situation by applying the Contracts Act 1950 and relevant cases.