How do we know that Lizabeth is on the verge of becoming an adult? Refer to several details from the text.

In the text, "fourteen-going-on-fifteen as I recall that devastating moment when I was suddenly more woman than child", Lizabeth is taking about getting her first period, which is a biological sign of a puberty.

Explanation:

In the text " I was still child enough to scamper along with the group". Lizabeth does not consider herself to be part of the group of children for the most part, signalling her adolescence.

In the text "wanting to join the fun and feeling that it was all a bit silly", Lizabeth's recognition of this activity being silly is signalling towards maturity.

In the text " The child in me sulked and said it was all in fun, but the woman in me flinched at the thought of the malicious attack that I had led.". This is a clear indication of her ascent into adolescence.