The Prophet ﷺ said, "It is not lawful for a woman (at the time of wedding) to ask for the divorce of her sister (i.e. the other wife of her would-be husband) in order to have everything for herself, for she will take only what has been written for her."
عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَحِلُّ لاِمْرَأَةٍ تَسْأَلُ طَلاَقَ أُخْتِهَا لِتَسْتَفْرِغَ صَحْفَتَهَا فَإِنَّمَا لَهَا مَا قُدِّرَ لَهَا