Is it permissible for a Muslim or Christian woman to allow her ex-husband to visit their daughter in her home and stay there overnight due to him having no other place, in her absence, and is her current husband's approval of this considered dayouthah (cuckoldry/lacking protective jealousy)?

The father must be allowed to visit his daughter and sit with her, either in her home if the owner permits, or outside of it. There is no objection to him staying a day or more in the house with his daughter if the woman (the stepmother) is not present. This is not dayyutha (cuckoldry) but rather an aid to goodness and upholding kinship ties. However, if the woman is present in the house, it is not permissible for the father to spend the night with his daughter in the same shared house unless there is a mahram for the woman present, and her husband is not allowed to permit this.