as one imagines.

She has the normal human failures of jealosy, getting into a secret engagement which for a woman was a bold step at that time where only women like Lucy Steele would be bold enough to get into.
Then acting like a gothic heroine with her 'sorrow', like Marianne and getting very ill. No self control on her emotions.

Above all fooling a whole village - willingly or unwillingly is not the point.
We lay the blame at Frank Churchill's door for the whole 'fooling' bit, but she was as much a part of it.

She came all the way to Highbury precisely to be there while Frank too would visit, and 'not tell'.

If she felt as guilty as she says, she would have gone off to Ireland and whiled her time till Frank Churchill came to a decision.

I don't mean to accuse her of the above things.
Just meant to point out that I don't see her as someone not deserved by the likes of a Frank Churchill.