Is it considered disobedience to one's mother if I go against her opinion regarding the wedding date, given my desire to marry and my fiancé's desire to marry after Ramadan, while her desire is for the summer?

If the husband wishes to expedite the consummation of the marriage, having paid the Mahr or scheduled its payment, then obedience to him takes precedence over obedience to the mother, and the husband must not be prevented from this. However, if the husband is not in a hurry, and the desire to expedite is the wife's wish, then she should try to persuade her mother, or encourage the husband to demand it. If this is not possible, then she must be patient until her mother gives permission, unless she fears falling into sin, in which case obedience to her is not obligatory, and disobeying her is not considered an act of disobedience.