You have or going to complete 26 weeks paid leave. You need more leave to make your baby comfortable. You can even resign if no extension of leave is approved by the employer. When you put the papers, the employer can very well ask for notice period. You cannot serve notice period; if you can, you would have gone to the office and once you make it up for a week, then you will get accustomed to it and may even think of continuing in the organisation. But the major question is whether the employer can demand the 5 months' salary already paid to you. And he answer for your major question is NO.The employer cannot demand you that you should pay the maternity leave salary paid to you. If you resign now, sometimes, they will retain this month's salary and adjust it towards the notice pay.
Now coming to the practical views, I would say that you should not resign and go. Women being very empowered should take it as a challenge.Obviously, if there are 50 employees in your establishment (men and women put together) you can demand for a creche and you will get 4 times to visit your baby and feed him/her over a period of 8 hours. This will solve more than half of your problems. At the same time, if you resign and go saying that I want to take care of my baby, then the question generally posed on the women will be "why didn't you think it before availing maternity leave with salary, when everyone knows that a baby of six months old will need the mother's care all throughout the day?" When all women start leaving the organisations who had given them employment at a time when employment was very important than their families then the employers will also start thinking that let the women take care of their families and we can abstain from hiring them. Should we give opportunity to employers to think kike this?????