Since I wrote and posted a recent head!canon list about Mockingbird!verse, I’ve got this vision in my head about the university years in Europe with Tim and the girls.
When Tim decided to go to university at Cambridge, the girls closest to him and who’d been his strongest support system (save for Dick) decided as a group to follow him there. The trio was made of Steph, Cass (Cain) and Tam.
Bruce, without hesitation and without taking “no” for an answer from anyone, paid for everyone’s tuition.
(Lucius almost convinced Bruce not to pay for Tam’s education, but a well-placed glare from and a smack up side the back of his head from Mrs. Fox silenced him before he could refuse Bruce’s offer. They still have one more son to put through college in a few years.)
Steph was a music major… Tam majored in linguistics… Cass decided not to go to university (her dyslexia makes it difficult to focus on the work required for school). Instead, she took the opportunity to experience living and working in England to develop a solid civilian persona/secret identity.
While Tim lives by himself in England, the girls end up living together with Beryl (Squire) in a large loft. The four of them become close friends and would end up working together to keep London free of crime.
(Tam would manage the command center and act as their version of “Oracle” while the other three were on patrol. Tim helped Tam get started and showed her how to get information and manage the others so they could fight crime more effectively… This, in small part, gave Tim the first small spark of inspiration towards creating his own Secret Six group and managing them effectively from afar.)
The four girls became lifelong best friends. This essentially the birth of the second generation of Birds of Prey, though they made frequent references to Charlie’s Angels, the Three Musketeers, and Powerpuff Girls during some of their adventures.
Initially, Beryl was out of the loop regarding Tim. She noticed the change in him, and how the others behaved around him. How they’d be supportive, but avoid all physical contact with him. She didn’t understand it, and no one would tell her anything regarding it.
Then, one day, there was a situation involving Tim and a female stalker obsessed with him as a Wayne. The stalker relentlessly pursued him, eventually leading Tim into having an acute emotional break. While Cass took care of the stalker and got her sent to prison, Beryl learned of what Tim had suffered from Tam and Steph. Once she understood what had happened, Beryl was able to help Tim better as well.
Unknown to everyone else, she’d been raped herself when she was a child. She understands that aspect of what Tim suffered better than the others. That ends up helping him a great deal in the long run.
During his years at Cambridge, Tim did not lack for people who cared about him and who wanted to help him though the trauma he’d been through. Between the girls, Dick, and Alfred, he was able to piece himself back together and get back to living a normal life…
…at least in outward appearances.