Hannah — As with most DA folk, I'd like to say that Padma is still friends with her. She may not have had many non-Ravenclaw/non-braniac friends prior to her time with the DA, but that experience taught her (somewhat) how to see value in things other than just pure intelligence. (Which isn't meant as a slight against Hannah (or anyone else) at all. Just rambling.) ANYWAY. At the very least, they have similar workaholic tendencies.
Roger — Ruefully, I am sure that, at some point in her Ravenclaw upbringing, Padma had a crush on him. These days, she likely looks back on such a time and wonders what the hell was wrong with her. ;)
Jackie — Padma wouldn't dare to intrude on any sort of patient-doctor confidentiality, but I'm sure she knows that Jackie treats Parvati and would be interested, on a professional level, about that. She trusts that he knows what he's doing, even if she forces herself not to ask for all the nitty gritty details.
Harry — Obviously Padma, like everyone else in the world, knows who he is. I don't imagine they were or are BFFs or anything of the sort, though he has earned the same respect that others in the DA have with her. As things seem to be changing with Harry, I'll leave that open for now!
Jace — I imagine that Padma has followed the evolution of Wicon with great interest, especially as it may effect her work in Healing. (I've previously played her as having great interest in melding both wizarding and muggle medicines, so if I go that route again, Wicon could be connected in some way?)
Oliver — Haha, oh, Patricia Oliver. Yeah, I recognize that storyline. ;) Padma likely reads the books, though she's not a vocal/rabid fan by any means. If she were to run into Oliver again, she'd likely ignore that she knew the secret entirely.