Do foster children inherit from the mother who has fed them?

Asalamualykum i would like to know do foster children inherit from the mother that fed them?what other laws apply to foster children and their foster parents?is it a rewardable act to breastfeed another child for eg if a family member has twins and a woman occasionaly comes to feed one of the twins in order to help and take the burden of the mother?is it an advisable thing to do in todays age? Jzk for mufti’s help