61a: the mishna said that if a brother of KOHEN GADOL dais he HOLETZ (v'elo meyamem). Which HIDUSH is that? Formerly, in the daf the gemara said: "hi haci SHOMERET YAVAM... and explain that "yevava his not ish'ah". It means that just in a widow it permits khoen who become khoen gadol to "lichnos" - and in yevane it's forbiden. So, we have KAL VAHOMER - if kohen (which become kohen gadol) asur in yevama - kal vahomer (in our mishna) that kohen gadol asur in yevame, isnt it?
61b: is it obvious from our sugiya that RIVKA was eldest from 3 years old (since we speak about na'arah), is there a way to settle RASHI in TOLDOT?
62b:RAV HUNA said: if he had sons which dais he already mame the mitva of PRIAH U'REVIA (since rav asi etc.)'. but, formerly, he explain r' natan that since Hevel dais, till SHT was born HAVA thought that she didn't made the mitzva (just then she got ZERA), isnt it a conflict?
1) Tosfos explains that the Chidush is that the Kohen Gadol does Chalitzah.
2) Rashi explains the word Na'arah from the root of Na'ar which means youth as in Shmuel I 1:24.
3) In the first instance Rav Huna is coming to explain the opinion of Rebbi Nasan.
Dov Zupnik