Should I get a letter of recommendation from my mother, who is a famous researcher in my field? My mother is a quite famous researcher (she has a PhD) on the field I want to do a PhD in. She works on the industry (not academia). I helped her on successful projects. She knows more about my work than my professors since we have worked much longer together.

Is it a good idea to ask for a recommendation letter from her? Since our personalities are very similar she can point out the high probability that I will be successful like her?
I would say no, this is a very very bad idea. Your mother going on about how likely you are to succeed will probably not carry much weight. What else would your mother say? If you were unlikely to be successful, would she say that? (even if she would, the perception of the people reading the letter will be that she would not)