may i answer them. the birthing system can be activated when our main character which is leah reach power level 100 or 200 ( you can check it in the pause menu, after you press it you will see the image of characters you have on the right. there will be HP, MP and power bar below each character's image).  in order for them to give birth the power bar(which is located below the MP bar) need to reach 100 or 200  or near both of them(for main character/leah) in order to give birth, 100 for valerie to give birth  and sanura birth hasn't implemented yet. the sign where you could make them give birth is the sign of a broken sphere on the bottom left of the character's image. 

to make them give birth you need to pause your game and press the skill button and choose which character  you want to give birth. you will be taken to a skill menu where two options await you. the first one written skill  and the second one written Damia's blessings. press the Damia's blessing one and you will see the option of give birth written as only birth. just press the birth option and the giving birth will starts

note: this option will only appear on Damia's blessings when the power bar reach 100 or 200  near the number(or whenever you see the broken sphere  on the bottom left of each characters).

oh yeah, i have to tell you that this game is still in development. so the maximum of the power you can raise is up to 300. but in order to make them give birth the game is only allowed leah or our main character to give on the power at 100 or 200, and valorie is still at 100 (because the power to give birth at number 300 hasn't implented yet). if you raise more than that the sphere on the bottom left of the character's image in the pause menu will be fixed and that means you have raise you character power bar until it reach one hundred more. if you accidentally have an excessive amount of power you receive, for example 103 or 203, that you could stil give birth. do not make your power bar goes beyond 300 for leah and 100 for valorie, otherwise you can make them give birth. if you accidentally get to many power and can't give birth, i  recommend you to use the blessing when you're in battle. it will appear as a pregnant belly icon in the battle.