From the following article:
<a target=_blank class=ftalternatingbarlinklarge href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1777828/
">http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1777828/
</a>
"ABSTRACT: Finger clubbing was measured in 73 of 105 patients with cystic fibrosis undergoing full assessment. The sign correlated well with the chest x ray score and indices of pulmonary function and infection but not with weight, height, age, liver function, or degree of fat malabsorption. The presence of clubbing suggests appreciable pulmonary involvement. Most probably its progression indicates a deterioration in pulmonary state. In both instances increased efforts should be made to treat the infection."
Yes, clubbing is a pulmonary symptom, often seen in CF (usually by age 2ish, according to the this website: <a target=_blank class=ftalternatingbarlinklarge href="http://chronicillness.suite101.com/article.cfm/living_with_cystic_fibrosis_cf)">http://chronicillness.suite101...th_cystic_fibrosis_cf)</a> and sometimes seen in other pulmonary/cardiac conditions. So if your daughter is experiencing clubbing, it does suggest lung involvement to at least some degree.
I don't remember when I noticed clubbing in my fingers, but I know I had it by the time I was in middle school or so. My guess is that I developed it well before I was conscious of it -- probably as an infant or toddler. I also had pneumonia as a child though (at 6 weeks, when I was diagnosed), so I clearly had pulmonary symptoms from the get go.