Ojousan vs. Oneesan

I was at work, and while I was walking in the hallway away from the main office, I met an elderly lady (in her 60's) going towards the office. She was looking for a co-worker.

When she met me, she called me a "kawaii ojousan" & then asked if I worked there.

What I want to know is why she would call me "ojousan" instead of simply "oneesan" or something else. Do older people use that term more often?

I thought it was only used for rich people, & I'm definitly not rich...

Elseve,

"Ojousan" is usually used in Japanese to mean "young lady" or "daughter", so it sounds like the obvious term for a 60-something woman to call you - assuming you are much younger than her. "Oneesan" is mostly used to refer to girls older than yourself, so it would have been strange if she had called you that - again assuming you are much younger than her.

Oneesan/oniisan are commonly used to address to young women/men in general, especially by the eldery people.

"Ojousan" is usually referred to a young unmarried woman/girl to early 20's. Also it can be referred to an inexperienced/innocent/spoiled looking.
"Oneesan" is one's older sister(not yours, which is referred often as "ane" to others) or that a young child may call you if you are older & in 20's. Also a man may call to get attention of a young waitress.
You feel old, if called obasan.
Then comes "obaasan".

Elseve,

In that context of a 60 something uptown woman addressing a young woman, "oneesan" would be bit of a less classier term.

Examples;

Chotto ojousan: Excuse me, miss.
Chotto oneesan: Hey, lady.

Kawaii ojousan: My, you're a pretty young lady.
Kawaii oneesan: Hey girl, you're lookin' good.

I love your examples, Uco-San.

Thank you for your responses!
It's clearer to me now :)

Elderly people have called me "oneesan" before, but Uco's probably right about the lady being an uptown woman so she simply doesn't use the term "oneesan."