Mom knows best. She has her opinion and no matter where she gets her facts from, she is obligated to voice her opinion. She can be wrong but that doesn't mean she has no right in saying what she says to her own children and their well being. Just because you guys grow pubic hair does not mean she stop worrying and caring. Let her yap her talk cuz without it, she might as well die cuz there is nothing else important in her life to keep her occupied.
I get it. She's old or old school so with that, understand where she is coming from, the old school of fork knocks which might be obsolete but her do her role as a mom as she continues to Yap the yap that gets no where.
You kids do what is best for you guys. It is your world so live accordingly. If you are tired of her yapping, tell her that you are tired of hearing it. Tell her next time she yaps at you about other people's problem, you are going to call the police. Bluffing the ignorant who doesn't know better might works. Old folks are afraid of the police.