Since so many people seem to think Catherine must be lying about her age, let's look at the evidence and end this once and for all.
This is Catherine in 2005, at 37.
Not perfect... a little rough, but she has been smoking like a chimney for years.
This is a series of screenshots from The Darling Buds of May. Catherine would have been 22 or 23 here. If you think that she's in her 40's now, then you'd have to think she was in her 30's then.
1987... so she would have been 18 in this photo:
Here's a playbill from when she was 16, in 1985... note they refer to her as a teenager:
1983
This is her in 1981 (in Annie)
Based on this photos, would you say that Catherine Zeta-Jones is lying about her age?