Is a woman who supplicates to God for Him to unite her with the one she loves considered to be in a state of necessity?

If the intention is to unite her with someone you love for marriage, which is permissible, then there is no harm in that. However, if the intention is to unite her with him for a sin, then it is not permissible to supplicate for that, because it is a supplication for sin, and Allah does not answer one who supplicates for sin.