What would you change?

If you were to change her C Skill the various skills that can replace it are going to be expensive/premium skills. Smoke and Wave skills can replace Savage Blow.

I'd throw Desperation 3 just to secure a follow up attack once her health drops due to Fury.

Desperation on B skill will be good on her. For C skill, it depends on what role she has for the team. As an ally supportive type, many 4* units have useful skills like tactics, drives, hones, or spurs. Which of these you use will depend on your play style. As a self supportive type, most of those skills are locked away in premium units like the wave skills but there other decent ones like threaten res or some smoke skills available from 4* units.

My Cousin Gave Her Threathen Res, So She Can Deal More Damage. Glimmer It's Ok, But I Think Moonbow It's Better.Like BuyMePizza Said.Desperation Could Work Great With Her,Or You Can Give Her Chill Spd, To Make Her Double An Ayra To.
If You Wanna Make Her Survive More, Than Deflect Seals Or Distand/Close Def Can Work, If Not Then Attack +3 It's Good.
The A It's Good, But Seeing That She Have The Poor Resistance And Defense Of 26, I Would Go For L&D.
This Is My Idea.

I run wolf effect,dd,vantage,threaten res and dd seal to secure cav kills.

Tank and kill reinhardt and lyn suicides herself easy peasy.

For the C-skill only? I was going to suggest brazen atk/def because you get 4 extra atk on vantage, which scales to 6 damage with effective damage, which can be the difference between live or die. But with 41 spd what the others say about desperation can be considered seriously, especially if you switch to a spd seal.