Is it sensible to tell a clingy mother that she might need to reconsider her excessive physical affection to a 12 year old? Considering that he is in a very sensitive and confuse hormonal phase is it not possible that he might actually get confused with all the issues of attraction etc..?

Yes, it is absolutely sensible and necessary to address this. A 12-year-old boy is entering a very sensitive stage, and excessive physical affection from a mother at this age is problematic and can cause confusion. The halacha is clear on this matter. According to the poskim, physical contact of affection with a boy at this age is already an issue. While touching that is not affectionate - for example, to calm him down or restrain him - is permitted, affectionate touching like hugging or kissing to encourage him is problematic at this age. If there is a real need for such contact, one can be lenient in a pressing situation, but only on parts of the body that are covered by clothing, not on the actual body itself. A mother needs to understand that her son is no longer a small child. At 12 years old, he is approaching bar mitzvah and is in the midst of serious hormonal changes. This is exactly the age where boundaries must be established for his healthy development. The excessive clinginess and physical affection needs to stop - not because there is anything wrong with a mother's love, but because the expression of that love must change as the child matures. You should approach this conversation with sensitivity but firmness. Explain to her that this is a halachic issue, not just a psychological one, and that continuing this way can cause real spiritual and emotional damage to the boy during this confusing time. He needs to learn proper boundaries between men and women, and that education begins at home with his own mother showing him what appropriate distance looks like.