Saeril was devastated at hearing this from the Master. This wasn't right and, while she was unaware of Yavanna having the same thought, the elder sensed that something bad was going to happen. That was when she realized that the mountain will become Thorin's undoing, as well as the horrid fate for Laketown.  

[i]Later on,[/i]
As the company was getting ready to leave for the Lonely Mountain on a barge, they had the weapons provided as they loaded their supplies, along with armor. 

Fili was just about to get on the boat, until he no longer felt his baby brother following him. Turning back, Kili was being held back by Thorin. Disbelief filled him that their uncle would split them up. Never in their childhood, have they ever split up; it was impossible. Right now, he felt despair for the first time. 

"Uncle, don't do this!", the elder brother jumped to Kili's defense. "We grew up on the tales of the Mountain, tales you told us; you can't take that away from him!", Fili narrowed his eyes at Thorin and went to get out of the boat to stand with his brother. "If you won't let him go, I stay. With him and Delva." 

Saeril looked up from her devastating period when she heard an argument amongst Thorin and the brothers. To top it off, Kili looked saddened. What was going on? What did Thorin say to them? Curiousity and concern filled her, resulting her to approach the remaining dwarves, and sit next to the brothers, placing a hand upon Kili's shoulder, trying to sooth him of his despair.