Is it permissible to supplicate for God to return the husband after separation, knowing that he has married another, and does his denial of the legal seclusion affect the judge's ruling?

It is permissible for a woman to pray to Allah to reconcile her with her former husband, and to take the necessary steps to achieve that, but without striving to cause separation between him and his current wife or asking Allah for that. If the husband is temperamental, has another wife, and the interference of his parents caused the marriage to not last, then it might be better not to consider returning to him to avoid a recurrence of problems. She can look for a righteous man to marry, and there is no harm in a woman offering herself for marriage to a righteous man, within the bounds of Islamic law. The most important thing is contentment with what Allah has decreed, for therein lies goodness and peace of mind. A valid seclusion (khalwa sahihah) is considered by some scholars to be equivalent to consummation (dukhool); so, if a woman is divorced after a valid seclusion and before consummation, she must observe the waiting period ('iddah) and is entitled to the full dowry.