I understand you might be wanting to respect first of all your mother and secondly the ambiguity you might be feeling around whether you should be feeling the way you seem to about these memories. There's a lot of good reason to be apprehensive about calling something you never thought of in that way sexual abuse. (Which can also make the realization in adulthood that much more startling.) But whether you should label it as such - which is a question motivated by why your parent seemed to be doing it - is maybe secondary to the question of whether it violated some physical boundaries. I don't know if this will help clarify but I don't think what you described is an ordinary thing to do. Hopefully this does not sound alarmist. You called yourself a prude. But aren't we supposed to be protective of our private areas? I don't think a parent of either gender is supposed to touch their child's private area - only in cases for medical or hygienic purposes until the child can perform those hygienic needs themselves.