As a 100 pound girl, I'd recommend a 9m bow/hybrid/SLE kite for her. My
boyfriend is 140 pounds and he rides my kite (9m Boxer SLE) a lot too.
Starting her off with a 9 or 10 meter would be your best bet and you can
always add a bigger (12m) kite later for the light winds. Make sure you
get her a kite with a lot of depower for safety - don't let her get an
old used kite off ebay...you get what you pay for.
As for a board, I would recommend something in the mid 130 range.
And make sure she takes lessons! Here's a good place for some discounted
Kiteboarding gear <http://www.mackiteboarding.com/sale.htm
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