A friends family member has passed and I was asked to make Dua. I’m not Muslim so I looked it up but am I allowed to do so? I didn’t want to be rude and reject without knowing for sure.
In contrast to Salat, Dua is a free form of praying that is not specific to Islam; Christians and Jews and other religions who pray to God also know free forms of prayer which are not necessaryly different from Dua of Muslim. If Christians pray to God (not Jesus or Mary or someone else), it may also be shared. At least, we already did so; it may not be common everywhere.
Someone who does not believe in God may stay present if others are praying; he may accept to be included in Dua but should not pretend to pray.