Liberal parenting dictates that parents do everything they can for their children but that the offspring take the goodies and run. Affection for parents is scorned - though not the money.
I do not think that this state of affairs benefits anyone. The parents are left exhausted, broke and bereft and the children turn into ungrateful, entitled narcissists without the support and guidance that came with the money in the traditional family.
Therefore, I have brought up my children differently and thereby reap the benefits.
The first thing to say is that males and females are different and have differing ideas of what make for an acceptable level of contact in a relationship. DDs are more mature and in need of contact than DSs, who often do not know how much support they need (as opposed to want.)
My DS, in his late 20's, still lives at home and, apart from a little daily contact, is happy to be very 'hands off'. However, if the DH and I go away for even half a week he misses us and it unsettles him. The DD has moved out for her job but has now bought a house 20 minutes away.
My DD is in daily contact and phones, often, three times a day.
The DH and I make it very clear to our children that we care for them and want to stay close even though we will not pester them when they need space. We help them all we can with cash and practical aid. We are always there with time and advice when they need us. They are, in turn, affectionate and caring and have turned out to be adults who are empathetic and with a sense of others' needs. They have avoided (so far) the pitfalls of liberal parenting that I have seen plague others: addiction, debt, giving up jobs when they become tedious or hard, permanent worldwide holidaying, shallow relationships, reliance on harmful friends and so on.
Coolgran65 is right to keep the channels of communication with her son open and should keep at it even if she meets a bit of resistance from him. (Just tell him it's because he is loved) He probably needs her as much as she needs him.