Is it better to give charity to employed relatives whose salaries barely cover their necessities, or to give it to the poor and orphans?

There is no harm in giving charity to relatives. You will receive the reward for charity and for maintaining kinship ties, based on the Prophet's (peace be upon him) saying: "Charity given to a poor person is charity, but given to a relative, it is two: charity and maintaining kinship ties." It is also recommended to allocate a portion of the charity for the poor and orphans.