When looking into profiles of a family member, I can read they graduated from high school but nothing about graduation from university.
I think it is sad.
Unfortunately, I play in Danish.
Here is the profile of Lilith Pleasant found while playing Angela:

Lilith graduated from Heron Institute:
Comments
The weird thing about education path in Sim Profile is that high school graduation is shown as soon as your sim meets another sim, but to discover others' university degrees, your sim has to ask about their degrees first. It can be found under Interests category.
And finally, once your sim attends graduation ceremony, their university thing is in career panel is removed. All of their degrees earned can be found in Simology panel (where traits can be found, but it is in a separate section).
I guess the milestone comes once your sim's graduation ceremony is over. As the game is in Danish, I'm assuming Heron is Foxbury there for some reason.
I'll try finding one graduated from Britechester.