Is my son who was breastfed one filling time by my aunt considered a brother to her children?

The baby who was suckled five sporadic times by a woman is considered a son/daughter of hers.

Is it permissible for the big brother to force his sisters to wear Hijjab(Islamic wear) if their father didn`t do his part in this regard ?

The father`s attention should be drawn gently and politely, and the sisters should also be reminded with good words since Allah, The Almighty, says: “O ye who believe! Save yourselves and your families from a Fire whose fuel is Men and Stones.”{Al-Tahreem/6}.

Is it a condition that the meat of the Eid sacrifice should be distributed in order for the sacrifice to be accepted by Allah?

The poor and needy should be given from that sacrifice , even if it be a small portion,(One kilo for example) as raw meat so that they would cook it the way they want. The remainder of that sacrifice is either distributed, eaten, or offered to people in a banquette .

Is it permissible for the person who wants to travel from the United Arab Emirates to Jordan during the day in Ramadan to break his fast before leaving his country; knowing that he had embarked on journey half an hour after dawn?

Praise be to Allah the Lord of the Worlds.

The person who made the intention to embark on journey after dawn must observe fast for that day, because it became an obligation on him before engaging on journey. However, if he experienced unbearable hardship while on travel, then he is permitted to break his fast, but he must make up for the missed day. And Allah The Almighty Knows Best.