Final answer:
Layla appears to be accustomed to her mother's work commitments taking precedence over leisure activities, showing a sense of expectation and slight disappointment, but still retains a lighthearted attitude towards the situation.
Step-by-step explanation:
Based on the provided paragraphs, Layla feels resigned and somewhat disappointed about her mother going into the lab on a Saturday instead of spending time with her at the beach. Her mother's work commitment appears to be a common occurrence, as implied by Layla's reaction, which suggests she expects this from her mother. Layla's teasing question, 'You sure you aren't going to the beach without me?' indicates that while she may be used to this situation, she maintains a good-natured attitude about it.