First Wife Wants to Have More Children Like the Second One
29-8-2021 | IslamWeb
Question:
Assalamualaikum Respected Shaik, a man has two wives. First one had 4 children when he married the second. Later the second got 4 children and the first six. The first one says that second wife got more than her. She gave birth only to two children after the second wife came the second one gave birth to 4 children. I want to ask is there anything like doing justice also for having children. Please help with your answer
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
We have already explained that a husband must be just between his wives, whether two or more, in terms of food, drink, clothing and housing, as well as being just with them in staying overnight with them.
For more benefit, please refer to Fatwa 90663.
The husband is not obliged to be just with them in anything else other than what we have mentioned.
Each wife has the right to have children, and it is not permissible to prevent her from her right in this regard. It is for this reason that the Sharee’ah forbids the husband from practicing ‘Azl (coitus interruptus) with his wife without her permission.
Ibn Qudaamah 
said in Al-Mughni while giving evidence for the prohibition of practicing ‘Azl without the wife's permission: “This is because she has a right to giving birth to children, and she is harmed by the ‘Azl; therefore, this is not permissible without her permission.” [End of quote]
Every wife should be content with what Allah has decreed for her of children and she should ask Allah Almighty to bless them for her and make them the comfort of her eye, and leave her affairs to Allah Almighty, for He is the One Who bestows offspring. Allah Says (what means): {To Allah belongs the dominion of the heavens and the earth; He creates what he wills. He gives to whom He wills female [children], and He gives to whom He wills males. Or He makes them [both] males and females, and He renders whom He wills barren. Indeed, He is Knowing and Competent.} [Quran 42:49-50]
Allah Knows best.