Legal Question in Family Law in Texas

In Texas, there is no legal limit. In most states, a limit like that is set up in that state's equivalent of the Health and Safety Code. However, just because there is no legal limit doesn't mean it's OK.

If the rental contract specifies a maximum number of residents, then there could be a rental contract compliance issue. That's between the landlord and the renter, though.

If the conditions in the apartment are abominable, then an argument might be made under the Family Code that the children's present circumstances present a significant risk to the children's physical safety or emotional well-being.