Why do you need credit from her?
You have known what for 17 yrs?
Why do you think she is jealous?
People say things that sometimes they mean to be nasty, and sometimes they say things just based on how they feel about things, and can come across as nasty whether they meant it or not. What makes you think she wants you as a servant for her son? How often do you cook? Do you consider yourself a good cook?
I don't understand why she would say something like that, its very rude. WHat did you do when she said that?
I don't think she is jealous that you can read, she may be more embarassed that she can't read. Has she asked you to cook and clean more? Do you feel like you cook and clean as much as you should? Many people look at cookbooks when they read, even if it's only to remember each thing that needs to go into the meal. There's nothing wrong with that and you shouldnt let that bother you. If thats what she believes then thats what she believes, and you just keep doing what you need to do so that you can make the meals you want to make.