Once again. What are you trying prove with the smoke thing? Tell me the science behind it.
If there's smoke coming from something moving really really fast it will look like a thin line trailing behind them like when a jet passes through a cloud and leaves a trail. However if it's an ordinary choo choo train the puffs of smoke would have enough time to exist the smoke stack while retaining their cloud shape. If the train went mega fast the smoke look like a straight line of smoke trailing behind until it dissipates.
Let me rephrase. If she was moving as fast as say Gai that smoke would look like a thin line trailing behind he because the smoke wouldn't have time to dissipate into any shape due to her speed.
The fact the clouds of breath are fully shaped show that the hot air of her breath had time to dissipate into the air enough to have that shape, otherwise it would just be a thin stream coming from the side of her mouth because the air from her breath would be just barely escaping her mouth.
There's also the fact that her voice traveled to Naruto before she did while she was already on her way there. Common sense would dictate that this means Kaguya was moving slower than Rock Lee vs Gaara.