Is it permissible to differentiate between two wives when attending occasions and Eid celebrations based on the request of one of them who refuses to be present with her co-wife, with the resulting division of children and the deprivation of some of them from participating in family occasions?

This matter does not necessitate justice. Your wife should agree to attend your relatives' occasions, and she does not have the right to prevent you from bringing your children. We advise you to act wisely and try to convince your wife to attend and meet her co-wife so that the children may bond and not be affected by the mothers' jealousy.