Lillah and charity

Giving sadaqah

Q: I am a student with only a small income from a part time job, mostly living on scholarships and financial assistance from family members who support my studies. In this case, will it be ok for me to give money to sadaqah? Or would that be disrespectful to the people who give me money to support my studies?

Sadaqah on behalf of the deceased

Q: I seek some advice from you insha'Allah. My mother is ill and I wish to give some charity on her behalf with the intention of earning Allah's pleasure and asking Him to cure my mother through the blessings of this act. Is this fine? Also, does the charity fall under Sadaqah or Lillah? Do you advise a specific amount of which I should give in charity or will any amount within my means suffice?