“I’ve come so far — I shan’t give up”
This snail is clearly signalling the letter P (for ‘prize’) in semaphore. I’m just sorry I couldn’t stay to transcribe the entire message. If I may hazard a guess, I imagine she was quoting John Bunyan.
And though she doth but very softly go,
However, 'tis not fast nor slow, but sure;
And certainly they that do travel so,
The prize they do aim at they do procure.
Extract from Upon a Snail, by John Bunyan