On our trip in Nov. my niece had her hair braided by a woman who approached us at Caramba restaurant--maybe not the greatest way to find someone, but she did a good job and it worked out. She said her fee was $40 US but she would do it for $30. We ended up paying her $40 anyhow because she did such a nice job. I'm sure the people at the office of wherever you stay will be able to set you up with someone. There are lots of locals who offer this service. Enjoy!
Sam