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.
If the intention behind celebration, slaughtering and distributing sweets is to feed the poor, it is a good matter and there is no evidence that prohibits it. If the intention is to thank Allaah The Almighty, for example if a wife gets rid of an immoral husband, then, that will be a good matter by virtue of the general proofs indicating the virtue of thanking Allaah. However, if the intention is to show happiness and joy for terminating the marriage contract without a Sharee‘ah-approved justification, then, this act should not be done because it is a form of happiness at something which is evil. The Islamic Sharee‘ah urges us to celebrate marriage, not divorce. So, the intention behind such a banquet will be invalid. The matter will be greater if the woman is sinful due to obliging her husband to divorce her because of her ill-conduct. In such a case she is glad about an unlawful matter and it is impermissible for a believer to be glad about unlawful matters.
Allaah Knows best.