Fasting While Breasteeding
Question :

I am breastfeeding in Ramadan. Is it obligatory on me to fast while breastfeeding?

Answer :

If fasting harms the woman who is breastfeeding by greatly decreasing her milk, or stopping its flow, then it is permissible for her not to fast. She should make up the missed fasts before the next Ramadan. Furthermore, a sum of 900 grams of food like wheat, oat and rice must be paid to the needy believers for each missed day.

Relations by Breastfeeding
Question : Is it permissible to breastfeed the child during the state of Janabah?
Answer : Yes, it is permissible.
Relations by Breastfeeding
Question : What is the age limit for a baby to be allowed to be breastfed?
Answer : It is permissible to breastfeed the child even if he/she exceeds the age of two years.
Relations by Breastfeeding
Question : Is there any concept of adult breastfeeding in Islam, so that the person becomes Mahram?
Answer : The breastfeeding that makes the person Mahram is for children under the age of two. After the age of two years, breastfeeding has no such effect.
What has been reported in some books of such an effect from women breastfeeding adult men has no basis in Islam.