My recommendation is to use up your paid maternity leave without telling the company of your intention to quit. After you have used up your paid maternity leave, then tell the company you decided to stop working because of the demands and responsibility of caring for your new child.
You may believe right now you want to stop working, but something could change during the three month maternity leave period that causes you to reassess the situation. Your company will not think ill of you for the last minute notice. They will have been without you for three months already and still be there.
It might even be a relief for you to wait out the three months, go back to work and then give your company the customary 2 weeks notice. After three months of motherly anxiety and stress, two weeks at the workplace might turn out to be a nice vacation.



