Tirza assumes that her removal of the rib bone is what has caused the skeleton to collapse and it sends a jolt of joy throughout her body. She did that. She holds the bone in her mouth for a moment, turning to her brother with her head and tail held high in triumph, before she turns back to see the shadowy figure approach. Gravitas joins her, the presence of his body beside hers inflating her bravado even further. Tirza tilts her head as she watches the stranger approach, trying to puzzle out who he is.
To the question about whether they were proud of themselves - the answer is a pretty obvious one though. She just blinks up at the star-strewn stallion and utters an incredulous “Yes.” around the bone in her mouth. Of course she is proud! She had toppled that skeleton? That was easily one of the coolest things to have ever happened to her so far.
While they are being asked about their mother, Tirza lowers her head and finally (carefully) places the rib on the ground by her hooves, nudging it fondly before lifting her head back up. Her snake eyes are narrowed in suspicion when she returns her attention to this stranger and she’s grateful that her twin seems to be of the same mind.
If Tirza could tell time, she would know that there had barely been enough a few seconds for them to answer about their mother (not that they were going to) before the stallion started getting all impatient. Like her brother though, the scaled filly just asks one of her own questions instead of answering the one that had been posed. “How do you know our mother?”
T I R Z A

@[stave]