All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Divorce is valid only from the husband; therefore it is not valid before the marriage contract, neither when the man says to a woman “you are divorced” nor when he conditions the divorce on the occurrence of something. If a man conditions the divorce of a woman on a given condition and after that he marries her, the divorce does not take place if the condition takes place.
Ibn Qudaamah said (in his book Al-Kaafi): “It is not valid to condition divorce before marriage; so if a man says to a nonrelative woman, ‘If you enter the house, you are divorced’, and then he married her and she entered the house, she is not divorced, because it was narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: “There is no divorce nor emancipation (of slaves) with regard to what the son of Aadam does not possess, even if he specifically mentions her by name.” [Ad-Daaraqutni] Another narration reads: “There is no divorce with regard what a man does not possess.” [At-Tirmithi, who said: Hasan [good] Hadeeth]"
The view that divorce does not take place at all, whether with or without a condition, is the view of the majority of the scholars as we have already clarified in Fatwa 92710.
Based on this, it is permissible for you to marry that girl. However, we warn against taking lightly the matter of uttering the word of divorce. You should be keen on building your family on sound foundations that will be a cause for the stability of your family, by having a mutual understanding between you and your wife, and each one of you should be tolerant about the mistakes of the other and fulfill his/her rights as best as he/she can.
For more benefit on the rights of the spouses with respect to each other, please refer to Fataawa 85308 and 83157.
Allaah Knows best.