Final answer:
Beryl Stapleton reveals her discontent with living on the moor through her conflicted desire to both leave and stay, indicated by her question about rolling Balancing Rock and the deep-blue fire in her eyes.
Step-by-step explanation:
The line that indicates Beryl Stapleton is not happy living on the moor is: "Shall I go roll Balancing Rock?" Her question, posed in a light manner but with a deep emotional undercurrent portrayed.
By the deep-blue fire in her eyes, is followed by a sigh and a dual expression of desire to both go and stay.
This interaction demonstrates her conflicted feelings about her life on the moor, suggesting she does not feel content or fulfilled.