You are never too old to have your hair braided, but there is a time frame when it should not be done. Below are my opinions on hairbraiding:
If you are between the ages of 6-18, then hairbraiding looks cute.
If you are 60 years or older, then hairbraiding looks cute.
If you are male, then a braid here and there is kinda cute.
If you are a female, then a few braids are kinda cute.
If you are a female between 18-59, full hairbraiding will never ever look as cute as Bo Derek. Frankly, it will look more like Bo Diddley!
co*ka
(For the record, I have seen a few women in the 18-59 category where it looked good).