Solar is known among the Dew Surfers for being the most bitter. While normally she's silent and an observer, whenever she speaks she's harsh with a sharp tongue toward most with her sister Sundown typically being the exception. However, here she's clearly annoyed about the concept of bringing in more cubs, due to her personal dislike of them. So while she still carries a mean and closed off tone, it's more haste, due to it being Sundown. And if anything, she's a good sister...relatively. 

Make sure to record this line at least twice! I'll be picking the best audition take to be the voice in the comic!