How to make babies come faster

It is not clear what you mean by that so I will answer all of the possibilities...

To add babies to your town you must have available Population slots, which means leveling your town. If you are presently at max population (tap the counter on the Status Bar at the top center of the screen to check your population and when it will increase).

Once you have an available slot for Population you place the baby Cradle in the home of a married couple (same sex marriage works too) and then you tap the cradle to initiate the timer to deliver the baby. To speed up the timer you can spend Life Points - simply tap on the timer on the cradle once it is active and then spend the LP to skip the timer.