Is the foster mother considered a kinship (rahim) like the biological mother, and what is her ruling?

A mother through suckling is not considered a blood relation (rahim) like a mother by lineage. She shares only four matters with the latter: marriage (nikah), looking (nazar), seclusion (khalwa), and being unmarriageable (mahramiyya). The obligation of upholding ties of kinship (silat al-arham) is not established through suckling.