this doesnt change the fact that the 1.2 x sp.def is much bigger then the 2.3x defence.
30 is about 2.7x 11
so that 1.2 is almost 3 times bigger then the 2.3 def.
Like I mentioned with the Shuckle example, with defenses, raising the LOWER defense is always more beneficial, even if that defense is HP.
I know her stats would increase more with a +SDef personality, but as I mentioned in my wall of text, it simply just doesn't help as much as if she were to have a +Def personality.
Simple, let's look at this. Take 1 stat point and divide by 56 which is her minimum defense, then multiply by 100 to get the percentage. That percentage is 1.78%
Special defense. Take 1 point and divide by 306 which is her minimum special defense and multiply by 100 to get the percentage. That is 0.32%.
Looking at this example, it proves that when you're putting EVs into a lower stat, is just simply counts for more. Then with personality, you multiply that by 1.1 and you get more of those stat points that count for more rather than ones that will help a bit, but not much.
This is why we use Bold Blissey.
Does that makes sense now?