1. The “fast of the first-born” of Erev Pesach is an obligation only upon sons. Daughters, however, are exempt from this fast (Shulchan Aruch and Mishnah Berurah 470;Ben Ish Chai and Kaf HaChaim).
2. A first-born who completes a tractate of Talmud [i.e., he is “making asiyum”] on this day is permitted to eat and is exempted from his fast. The custom is that those first-born who are not themselves completing a tractate participate in the siyum meal conducted by others and they are thereby allowed to eat. However, it is important that they be present at the actual completion of the study and not just at the time of eating. They should also understand what is being said by the person who is completing the tractate. A first-born who did not personally participate at all at the siyum may not eat by merely having others bring him food that was served at thesiyum (Acharonim).

