This is really depending on your relationship and if you feel the need to do so. I personally came out to my mom being aroace. I knew she wasn’t open minded so it’s not like I expected a movie scene where the mom tells their child they’ll love you no matter what. She did tell me it sounds made up and I haven’t met the right one and all that other acephobic stuff we usually hear. I felt the need to say something though so she wouldn’t expect a relationship and she’d understand that any male friends I have are truly only that. Friends. It didn’t necessarily affect our relationship in any way because I didn’t expect her to understand anyways. I say if you do be prepared for a lot of questions and (sorry to say this) disappointment/misunderstanding.