A Dilemma of Appearance

I'm 24-years-old but regularly assumed to be anywhere from 14 to 18 years of age (18 is on a lucky day).  I'm well acquainted with shocked reactions of people who card me and awkward moments in which the manicurist asks if Best Girl Friend is my mother (morons.) 

Sometimes I embrace the advantages (I was still offered crayons at restaurants till recently; I can let people assume it's okay I don't have a degree yet, etc.) and other times I have to brace myself for possible challenges.  Acting gigs are one of my major challenges.  While it's great that I'll most likely be passing as a 21-year-old by the time I get to 40, for now my *youthful* appearance is a pain in the arse.

A few months ago when the movie opportunity came along is a prime example. The casting notice called for 25-30somethings, and an actress friend told me to give it a shot.  She'd already been cast as an extra.  I originally planned to submit what I considered a good head shot (a photographer did it about a year ago):

 

but she suggested the shot looked too young.  So we settled on this:

The difference in the two pictures is about a year, so maybe I have aged slightly (finally :-p).  I submitted it, and the casting agent called me "cute" and seemed delighted, but suggested it was possible to style myself older.  She said I had the job, and would need to look 30-35 the day of the shoot.  I freaked out, but worked with my friend to pick make-up and wardrobe that would give me as much advantage as possible.  This is how I looked the morning of the shoot:

Then last weekend I was preparing for an audition that called for a "20something."  BGF (who's a licensed cosmetologist) thinks I look older with my hair up and less eyeliner, as modeled in this look:

 

and I got the part. :-)

Have any of you ever encountered a major obstacle with your appearance or age, especially one that interfered with obtaining a job opportunity?  How did you handle it?