Shyvana in general is doing very poorly in this current meta. Much of her struggle stems from having no real CC in her kit, but requiring her to sit on top of the enemy while she tears them to shreds. If you need help understanding why this is a problem, look at Jax or Irelia. Both have abilities that increase survivability, both have dashes and leaps and stuns to keep their enemies where they want them. Comparatively, Shyvana trades all of that off and still doesn't have the tankiness or high damage values she needs to survive in fights. She has no form of sustain, and in general her only strength is her movement speed on her W. She can't duel most junglers until after level 6, and even then her scaling has her peak at mid game and fall back behind others late.
Now this wouldn't be a problem if she could farm jungle and outscale the enemy team, but she can't because Riot has almost completely destroyed the jungle farm meta in favor of flashy plays and ganking champions. The fact of the matter is, Shyvana was designed to be a mid-late game raid boss that was almost on a Nasus level of difficulty to kill, but Riot has clipped her wings so-to-speak by nerfing jungle XP, jungle camp timers, and pushing ganking junglers back into the meta to get xp and gold.
I have to disagree with you. She needs a full rework before anything else. A cc-less champion with mediocre damage values and a kit that doesn't hold a candle to modern champion kits will cease to function moving forward. Riot needs to focus on one thing with her:
FARMING RAID BOSS
Don't force her to have to gank because there are no more camps left to kill/steal. Give her incentives to stay in the jungle, help when needed, but also give her the tools to deny the enemy junglers. When played perfectly, she should be able to come out 2-3 levels ahead of the enemy team and the enemy team should be looking for ways to stop her in the jungle.