Well, from a mother's point of view (as I am old enough to be your mom) I agree with mouthy that there may be risks involved and to look into it very carefully before making a final decision, but you said you only want to get a small tattoo so I shouldn't think that would cause much harm if done by a qualified tattooist, and a little flower on your shoulder would look pretty.
I also think - hey, you only live once and after years of denial as a JW, if it is really what you want then go for it girl!! You are certainly not too old!!
Isn't it wonderful to be free to live life and have fun !!!