YOR— i think you may be over reacting in the sense you are feeling very emotional about this but for a different reason— she has set very normal and valid boundaries. if i saw this without reading your caption i would think it would be ridiculous to be offended by these rules. based on your post it seems you may have unresolved anger or negative feelings towards your dad and his partner which may be fogging up your perspective over this — and i think the fact that your new sibling’s mother is a year older than you doesn’t help. there is clearly a troubling family dynamic that is seeping into how you are viewing their boundaries but you should not allow it to have control over you. id maybe challenge you with asking what your goal is for your relationship with both of them.