Setting aside the Captain Wentworth factor for a moment, I think we can see a steady improvement in Anne's spirits and situation.

In the beginning at Kellynch, she's marginalised, even Lady Russell doesn't cheer her up, and she only speaks in occasional one-liners. OK, the bit where she warns Elizabeth about Mrs Clay would be more than a one-liner, but we don't get it as direct speech, and it's only a chore that she undertakes out of duty and prudence.

Then, at Uppercross, she gets quite chatty with Mary, and is of secondary value to several people (confidante for their complaints about each other, nurse, pianist for their dancing, etc), which is better than nothing, or being 'only Anne' (ch1). When she imagines that the Crofts' style of gig-driving is like their marriage, it's her first piece of humour that I've noticed.

At Lyme, she notches up five more pieces of humour in her own quiet way. She also faces an interesting decision about how to treat Captain Benwick. Reach out to this virtual stranger, or draw back from him? I find it interesting because her behaviour has mostly run on rails so far - duty, prudence, and propriety - but this is more of a free choice. In reaching out to him, she becomes of primary value to someone, and he even starts behaving like an Admirer. The wind-assisted bloom attracts another admirer, and the aftermath of Louisa's fall proves Anne's value to... well, to practically everyone.