the first child is a learning curve.
Here in the U.S. a normal delivery usually allows the mother 48 hours in the hospital, then it is wheelchair to the car, and then home. Back when it finished nursing in the 1960's it was the 5-day "vacation". One physician I know who delivers in a rural county in his "office", has the women stay 24 hours just to monitor for any problems. Mid-wives here can deliver at the home -- so no "vacation" time.
the First child brings a lot of anxiety, a lot of adjusting to the new-born and needs. Sleepless nights if breast feeding. That is why mothers need the "maternity leaves". And as you found, age 8 to 12 weeks can make a huge difference.
A doctor friend of mine, after having a single, had twin girls. She had friends who allowed her to continue her job as Emergency Room Doctor. But it took 4 of them at a time to care for the twins and the cooking, and care for the house, and the older 2 year old child.
The Second Child is "Old Hat", so gets "express" care