So where do we begin? Let's start with the fact she should be an all rounder, dual wielding magical swordswoman, since this is how I have imagined her in my series.
What problems arise as a result? Well, her stats all end up getting jumbled a bit off of the norm. However, she is still superior to anyone outside of her familia, in terms of potential. Because of this, I'll give her an average of 750 points in every stat, for the first 3 levels, I won't give her the 999, because her focus would be directed more towards an even spread due how demanding the fighting style is. Once she reaches level 4, I feel like if she really tried to push for it, she could reach the cap, and this leaves enough room for Maxim to still be just barely stronger than her, despite a full level's worth of difference between them. And at level 9, she'd only realistically have enough time to reach 750. At least this is how I see it.
What does this translate to?
All stats : Lvl 1-3 = 750 each
: Lvl 4-8 = 999 each
: Lvl 9 = 750
Total: 750 * 4 + 999*5 + 8 * 300 = 7995 + 2400 = 10395
According to the scale this puts her right within the mold of a Pseudo lvl 10 in all fields of combat right away as a base line!
Now, let's account for the other things:
Afterglow +1 full level
D rank Swordsman +3 full levels
H rank Supreme Strike +1 Level (This might be more, due to supreme, but better to low ball it.)
At least 1 Skill that boosts a full level against dragons.
At least 3 other skills, each giving enough that, together they should be enough to boost out of Pseudo level x, to reach level x
Addon totals: +5 Levels & Pseudo->full
Against dragons +1 extra
So, Empress is actually a level 15 in normal combat, and level 16 in combat against dragons.