Ehm...I think you are mixing some canon material up here....
Ki Adi Mundi deflected 2-3 blaster bolts before dying. And he's a high council member. Obi-Wan Kenobi survived Order 66 by sheer luck. Quinlan Vos was mortally wounded.
And this was against teams of 3-4 Clone Troopers. A Jedi has a maximum of blaster bolts he/she can deflect. Did you see the mass of soldiers PLUS Darth Vader enetering the temple? There is NOTHING to gain against that army.
Suppose the Temple is a big place. Who says she didn't try to fight her way through a few waves but was simply too late? Remember, the one who actually KILLED the younglings was DARTH VADER. Brought to their chambers by at least a platoon of troopers. A Sith Lord and an army? Good luck with your little laser sword. No Yoda or Luke would have made it.
In the comics and cartoons, Jedi can deflect a million blaster bolts. In the movies (which are higher in canon) they can't. And we are talking movies here, where people die when gunned at by 10 troopers. Anyone would.