If a person is of illegitimate birth and has many half-siblings due to the inappropriate actions of their mother, what is the extent of family ties and responsibility towards those siblings?
Keeping ties with relatives and being kind to them is incumbent upon a Muslim, even towards their close relatives if they were non-Muslims or of illegitimate birth. However, keeping ties does not always entail visiting them and contacting them on a frequent basis, rather it is sufficient to keep ties with them by sending them greetings and asking about them through any form of communication that you feel comfortable with. Yet, if being close to them can negatively impact your faith and moral character, then you must limit the communication to the extent that will not have a negative impact.