I'd be reporting her but that's just me, personally it's none of anyone's business what's going on with me, if I want to share things then I will but it's not up to someone to keep asking me
As far as commenting on your appearance, personally that's just rude especially if it's in front of others, I myself suffer from bad skin an when stressed it flares up, if someone was commenting on it in front of others I'd be shutting them the fk up there an then
She seems to be way over stepping boundaries, nothing to do with age, she just seems to be a noisy person which some people are, have you spoken to her privately an told her you don't want to share information an she's being disrespectful to you with commenting on you in front of others? I'd say tell her you feel uncomfortable an it's not her business what's going on an to stop with her comments on things, an if not then it needs to be reported, the last thing you want is to be harassed just because she wants to know whats going on