I agree with everything you said about your coworkers parenting skills. She definitely has problems with parenting and socializing herself -seems like a very bold person. Whether to give her your honest opinion, depends on how much she asks you, but if I were you, I would tighten up your boundaries. If she comes without being invited, tell her not to do that and when she gives TMI, call her on it.

I agree it's very weird to discuss looking for her son's puberty signs and speaking about his erections with the nurse -talk about embarrassment - it's hard to tell if she's really concerned or just bragging that her son's a normal functioning boy. I have daughters and I wasn't about to examine my child for signs of puberty.

How much you tell her depends on whether she'll handle the info or hold a grudge, where this could affect your working relationship. If you're not worried then you could tell her, you're not into the friendship and she'll back off.

Her parenting style sounds like a mix of 'helicopter parent', 'I'm your best buddy parent' and some dysfunction scattered in there. You're right about being isolated and her hovering/enabling/lack of boundaries as a parent has affected the way this young man is and how he struggles. She involves you and other workers because deep inside she needs validation probably, even though she's not looking for disagreement. So you're right in your assumptions, but you really should be honest and set boundaries. Do you know why she's alienated with her family?