What should I focus on to keep improving her

Here is my Midgame Level 50 Miyabi Build (Can't Level her up yet, because I started playing 2 weeks ago, but was super lucky winning all my 50/50s). Mainstats are: HP, Atk, Def, Crit Rate, Ice Dmg Bonus and Atk%

Here is my Midgame Level 50 Miyabi Build (Can't Level her up yet, because I started playing 2 weeks ago, but was super lucky winning all my 50/50s). Mainstats are: HP, Atk, Def, Crit Rate, Ice Dmg Bonus and Atk%