Fatimah sent a text message to her friends via the Whatsapp Group application on 8 November 2019 stating:

Want to sell a Honda Jazz car for RM90,000.00. Anyone who is interested, please text me your agreement before 12 November 2019.

As soon as she read the text message, Sofea sent a text message to Fatimah as follows;

I agree to buy your car at the stipulated price but payment will be made in two installments.

Fatimah, however, did not reply to the text message from Sofea. Two (2) weeks later, Sofea found out that Fatimah had sold her car to Mariam. Sofea was not happy with Fatimah's action and demanded that Fatimah give the car to her as she had already agreed to buy Fatimah's car as soon as Fatimah offered it through the Whatsapp Group application.

Before Mariam could pay the price of the car that she bought from Fatimah, Mariam fell ill and was hospitalized. After six (6) months, Fatimah demanded payment from Mariam. Mariam who had to pay high medical bill now does not have enough money to pay her debt to Fatimah. Mariam sent a letter to Fatimah stating;

I can only afford RM87,000.00. If you agree to the payment, please cash check enclosed with this letter before 20 June 2020. If you do not agree, please inform me and destroy the cheque.

Fatimah cashed the cheque she received from Mariam on 19 June 2020. A month later, Fatimah demanded the balance from Mariam but Mariam refused to pay.

Advise Fatimah regarding the above situation. Support your answer with the relevant provisions in the Contracts Act 1950 and decided cases.