What is the ruling on visiting a female cousin on Eid, and is it obligatory to visit her if she is immodestly dressed (mutabarrijah) and without a mahram?

It is unlawful for a man to be in seclusion with or look at a non-mahram woman, such as a paternal cousin, if she is displaying her adornments or if being in seclusion with her leads to temptation. This applies whether it is during Eid or any other time. A paternal cousin is not obligated to be visited as part of upholding kinship ties, because those whose kinship ties must be upheld are limited to those with whom one has a prohibitive degree of kinship by lineage.